diff --git a/grammar/MetaPrompt.g4 b/grammar/MetaPrompt.g4
index 6694983..f85be81 100644
--- a/grammar/MetaPrompt.g4
+++ b/grammar/MetaPrompt.g4
@@ -2,11 +2,8 @@ grammar MetaPrompt;
 
 prompt:	exprs EOF ;
 exprs: expr*? ;
-exprs1: expr+? ;
-expr: LB expr1 RB
+expr: meta_body
     | text
-    | RB
-    | LB
     | COMMENT_KW
     | META_PROMPT
     | EQ_KW
@@ -19,23 +16,18 @@ expr: LB expr1 RB
     | WITH_KW
     ;
 
-expr1
-    : meta_body
-    | exprs
-    ;
-
 meta_body
-    : IF_KW exprs THEN_KW exprs ELSE_KW exprs
-    | IF_KW exprs THEN_KW exprs
-    | CHOOSE_KW exprs option+ default_option?
-    | USE named_parameters
-    | META_PROMPT exprs
-    | COMMENT_KW exprs
-    | var_assignment
+    : IF_KW exprs THEN_KW exprs ELSE_KW exprs RB
+    | IF_KW exprs THEN_KW exprs RB
+    | CHOOSE_KW exprs option+ default_option? RB
+    | USE named_parameters RB
+    | META_PROMPT exprs RB
+    | COMMENT_KW exprs RB
+    | LB var_assignment RB
     | var_optional_assignment
-    | VAR_NAME
-    | CALL call_arg1 call_arg*
-    | CALL call_arg*
+    | LB VAR_NAME RB
+    | CALL call_arg1 call_arg* RB
+    | CALL call_arg* RB
     ;
 
 var_assignment
@@ -43,7 +35,7 @@ var_assignment
     ;
 
 var_optional_assignment
-    : VAR_NAME EQ_OPTIONAL_KW exprs
+    : LB VAR_NAME EQ_OPTIONAL_KW exprs RB
     ;
 
 call_arg1
@@ -74,17 +66,17 @@ LB : '[';
 RB : ']';
 EQ_KW : '=' ;
 EQ_OPTIONAL_KW : '?=' ;
-META_PROMPT : [a-zA-Z_]?[a-zA-Z0-9_]* '$' ;
-COMMENT_KW : '#' ;
+META_PROMPT : LB [a-zA-Z_]?[a-zA-Z0-9_]* '$' ;
+COMMENT_KW : LB '#' ;
 CHAR : ( ESCAPED | .);
 fragment ESCAPED : ESCAPE ESCAPEE;
-fragment ESCAPEE : (LB | ESCAPE);
+fragment ESCAPEE : (LB | ESCAPE | RB);
 fragment ESCAPE : '\\';
-USE : ':use' WS+ [a-zA-Z0-9/_.-]+ WS*;
-CALL : '@' [a-zA-Z_][a-zA-Z0-9_]* WS*;
+USE : LB ':use' WS+ [a-zA-Z0-9/_.-]+ WS*;
+CALL : LB '@' [a-zA-Z_][a-zA-Z0-9_]* WS*;
 fragment WS : ' '|'\n';
-IF_KW : ':if' ;
-CHOOSE_KW : ':choose' ;
+IF_KW : LB ':if' ;
+CHOOSE_KW : LB ':choose' ;
 OPTION_KW : ':option' ;
 WITH_KW : ':with' ;
 DEFAULT_KW : ':default' ;
diff --git a/python/src/parse_metaprompt.py b/python/src/parse_metaprompt.py
index a4a102c..c3d29e2 100644
--- a/python/src/parse_metaprompt.py
+++ b/python/src/parse_metaprompt.py
@@ -18,21 +18,12 @@ def syntaxError(self, recognizer, offendingSymbol, line, column, msg, e):
         raise Exception(f"Syntax error at line {line}:{column} - {msg}")
 
 
-_pattern = r"\\([\[\\])(\[)?"
+_pattern = r"\\([\[\\\]])"
 
 
 def _escape_pattern(match):
     first = match.group(1)
-    second = match.group(2)
-    if second is None:
-        if first == "\\":
-            return "\\\\"
-        elif first == "[":
-            return "["
-        else:
-            raise ValueError("Invariant violation: _escape_pattern")
-    else:
-        return match.group(1)
+    return first
 
 
 def _process_escaping(string):
@@ -52,35 +43,18 @@ def visitExprs(self, ctx: MetaPromptParser.ExprsContext):
         exprs = []
         for expr in ctx.expr():
             expr_items = self.visit(expr)
-            exprs.extend(expr_items)
-        return _process_expr_list(exprs)
-
-    def visitExprs1(self, ctx: MetaPromptParser.Exprs1Context):
-        exprs = []
-        for expr in ctx.expr():
-            expr_items = self.visit(expr)
-            exprs.extend(expr_items)
+            exprs.append(expr_items)
         return _process_expr_list(exprs)
 
     def visitExpr(self, ctx: MetaPromptParser.ExprContext):
-        exprs = []
         if ctx.text() is not None:
-            exprs.append(self.visit(ctx.text()))
-        if ctx.expr1() is not None:
-            expr1 = self.visit(ctx.expr1())
-            if expr1["type"] == "meta":
-                exprs.append(expr1["meta"])
-            elif expr1["type"] == "exprs":
-                exprs.append({"type": "text", "text": "["})
-                for child in expr1["exprs"]:
-                    exprs.append(child)
-                exprs.append({"type": "text", "text": "]"})
+            return self.visit(ctx.text())
+        if ctx.meta_body() is not None:
+            return self.visit(ctx.meta_body())
         else:
             # a token is in a standalone position and should be
             # treaded as text
             for part in [
-                ctx.RB(),
-                ctx.LB(),
                 ctx.COMMENT_KW(),
                 ctx.META_PROMPT(),
                 ctx.EQ_KW(),
@@ -93,15 +67,7 @@ def visitExpr(self, ctx: MetaPromptParser.ExprContext):
                 ctx.WITH_KW(),
             ]:
                 if part is not None:
-                    exprs.append({"type": "text", "text": part.getText()})
-
-        return _process_expr_list(exprs)
-
-    def visitExpr1(self, ctx: MetaPromptParser.Expr1Context):
-        if ctx.meta_body() is not None:
-            return {"type": "meta", "meta": self.visit(ctx.meta_body())}
-        else:
-            return {"type": "exprs", "exprs": self.visit(ctx.exprs())}
+                    return {"type": "text", "text": part.getText()}
 
     def visitVar_optional_assignment(
         self, ctx: MetaPromptParser.Var_optional_assignmentContext
@@ -193,7 +159,7 @@ def visitMeta_body(self, ctx: MetaPromptParser.Meta_bodyContext):
             }
 
         elif ctx.USE() is not None:
-            module_name = ctx.USE().getText().removeprefix(":use").strip()
+            module_name = ctx.USE().getText().removeprefix("[:use").strip()
             parameters = self.visit(ctx.named_parameters())
             return {
                 "type": "use",
@@ -202,7 +168,7 @@ def visitMeta_body(self, ctx: MetaPromptParser.Meta_bodyContext):
             }
 
         elif ctx.CALL() is not None:
-            function_name = ctx.CALL().getText().removeprefix("@").strip()
+            function_name = ctx.CALL().getText().removeprefix("[@").strip()
             positional_args = []
             named_args = {}
 
@@ -260,7 +226,7 @@ def use_arg(arg):
                 "type": "meta",
                 "exprs": _process_expr_list(exprs),
             }
-            chat_id = ctx.META_PROMPT().getText()[:-1]
+            chat_id = ctx.META_PROMPT().getText()[1:-1]
             if chat_id != "":
                 res["chat"] = chat_id
             return res
diff --git a/python/src/parser/MetaPrompt.interp b/python/src/parser/MetaPrompt.interp
index 08e3beb..fd1df1d 100644
--- a/python/src/parser/MetaPrompt.interp
+++ b/python/src/parser/MetaPrompt.interp
@@ -5,12 +5,12 @@ null
 '='
 '?='
 null
-'#'
 null
 null
 null
-':if'
-':choose'
+null
+null
+null
 ':option'
 ':with'
 ':default'
@@ -43,9 +43,7 @@ VAR_NAME
 rule names:
 prompt
 exprs
-exprs1
 expr
-expr1
 meta_body
 var_assignment
 var_optional_assignment
@@ -58,4 +56,4 @@ text
 
 
 atn:
-[4, 1, 18, 150, 2, 0, 7, 0, 2, 1, 7, 1, 2, 2, 7, 2, 2, 3, 7, 3, 2, 4, 7, 4, 2, 5, 7, 5, 2, 6, 7, 6, 2, 7, 7, 7, 2, 8, 7, 8, 2, 9, 7, 9, 2, 10, 7, 10, 2, 11, 7, 11, 2, 12, 7, 12, 2, 13, 7, 13, 1, 0, 1, 0, 1, 0, 1, 1, 5, 1, 33, 8, 1, 10, 1, 12, 1, 36, 9, 1, 1, 2, 4, 2, 39, 8, 2, 11, 2, 12, 2, 40, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 3, 3, 60, 8, 3, 1, 4, 1, 4, 3, 4, 64, 8, 4, 1, 5, 1, 5, 1, 5, 1, 5, 1, 5, 1, 5, 1, 5, 1, 5, 1, 5, 1, 5, 1, 5, 1, 5, 1, 5, 1, 5, 1, 5, 4, 5, 81, 8, 5, 11, 5, 12, 5, 82, 1, 5, 3, 5, 86, 8, 5, 1, 5, 1, 5, 1, 5, 1, 5, 1, 5, 1, 5, 1, 5, 1, 5, 1, 5, 1, 5, 1, 5, 1, 5, 5, 5, 100, 8, 5, 10, 5, 12, 5, 103, 9, 5, 1, 5, 1, 5, 5, 5, 107, 8, 5, 10, 5, 12, 5, 110, 9, 5, 3, 5, 112, 8, 5, 1, 6, 1, 6, 1, 6, 1, 6, 1, 7, 1, 7, 1, 7, 1, 7, 1, 8, 1, 8, 3, 8, 124, 8, 8, 1, 9, 1, 9, 1, 9, 3, 9, 129, 8, 9, 1, 10, 1, 10, 1, 10, 1, 10, 1, 10, 1, 11, 1, 11, 1, 11, 1, 12, 5, 12, 140, 8, 12, 10, 12, 12, 12, 143, 9, 12, 1, 13, 4, 13, 146, 8, 13, 11, 13, 12, 13, 147, 1, 13, 2, 34, 40, 0, 14, 0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 0, 0, 169, 0, 28, 1, 0, 0, 0, 2, 34, 1, 0, 0, 0, 4, 38, 1, 0, 0, 0, 6, 59, 1, 0, 0, 0, 8, 63, 1, 0, 0, 0, 10, 111, 1, 0, 0, 0, 12, 113, 1, 0, 0, 0, 14, 117, 1, 0, 0, 0, 16, 123, 1, 0, 0, 0, 18, 128, 1, 0, 0, 0, 20, 130, 1, 0, 0, 0, 22, 135, 1, 0, 0, 0, 24, 141, 1, 0, 0, 0, 26, 145, 1, 0, 0, 0, 28, 29, 3, 2, 1, 0, 29, 30, 5, 0, 0, 1, 30, 1, 1, 0, 0, 0, 31, 33, 3, 6, 3, 0, 32, 31, 1, 0, 0, 0, 33, 36, 1, 0, 0, 0, 34, 35, 1, 0, 0, 0, 34, 32, 1, 0, 0, 0, 35, 3, 1, 0, 0, 0, 36, 34, 1, 0, 0, 0, 37, 39, 3, 6, 3, 0, 38, 37, 1, 0, 0, 0, 39, 40, 1, 0, 0, 0, 40, 41, 1, 0, 0, 0, 40, 38, 1, 0, 0, 0, 41, 5, 1, 0, 0, 0, 42, 43, 5, 1, 0, 0, 43, 44, 3, 8, 4, 0, 44, 45, 5, 2, 0, 0, 45, 60, 1, 0, 0, 0, 46, 60, 3, 26, 13, 0, 47, 60, 5, 2, 0, 0, 48, 60, 5, 1, 0, 0, 49, 60, 5, 6, 0, 0, 50, 60, 5, 5, 0, 0, 51, 60, 5, 3, 0, 0, 52, 60, 5, 18, 0, 0, 53, 60, 5, 11, 0, 0, 54, 60, 5, 12, 0, 0, 55, 60, 5, 14, 0, 0, 56, 60, 5, 15, 0, 0, 57, 60, 5, 9, 0, 0, 58, 60, 5, 13, 0, 0, 59, 42, 1, 0, 0, 0, 59, 46, 1, 0, 0, 0, 59, 47, 1, 0, 0, 0, 59, 48, 1, 0, 0, 0, 59, 49, 1, 0, 0, 0, 59, 50, 1, 0, 0, 0, 59, 51, 1, 0, 0, 0, 59, 52, 1, 0, 0, 0, 59, 53, 1, 0, 0, 0, 59, 54, 1, 0, 0, 0, 59, 55, 1, 0, 0, 0, 59, 56, 1, 0, 0, 0, 59, 57, 1, 0, 0, 0, 59, 58, 1, 0, 0, 0, 60, 7, 1, 0, 0, 0, 61, 64, 3, 10, 5, 0, 62, 64, 3, 2, 1, 0, 63, 61, 1, 0, 0, 0, 63, 62, 1, 0, 0, 0, 64, 9, 1, 0, 0, 0, 65, 66, 5, 10, 0, 0, 66, 67, 3, 2, 1, 0, 67, 68, 5, 16, 0, 0, 68, 69, 3, 2, 1, 0, 69, 70, 5, 17, 0, 0, 70, 71, 3, 2, 1, 0, 71, 112, 1, 0, 0, 0, 72, 73, 5, 10, 0, 0, 73, 74, 3, 2, 1, 0, 74, 75, 5, 16, 0, 0, 75, 76, 3, 2, 1, 0, 76, 112, 1, 0, 0, 0, 77, 78, 5, 11, 0, 0, 78, 80, 3, 2, 1, 0, 79, 81, 3, 20, 10, 0, 80, 79, 1, 0, 0, 0, 81, 82, 1, 0, 0, 0, 82, 80, 1, 0, 0, 0, 82, 83, 1, 0, 0, 0, 83, 85, 1, 0, 0, 0, 84, 86, 3, 22, 11, 0, 85, 84, 1, 0, 0, 0, 85, 86, 1, 0, 0, 0, 86, 112, 1, 0, 0, 0, 87, 88, 5, 8, 0, 0, 88, 112, 3, 24, 12, 0, 89, 90, 5, 5, 0, 0, 90, 112, 3, 2, 1, 0, 91, 92, 5, 6, 0, 0, 92, 112, 3, 2, 1, 0, 93, 112, 3, 12, 6, 0, 94, 112, 3, 14, 7, 0, 95, 112, 5, 18, 0, 0, 96, 97, 5, 9, 0, 0, 97, 101, 3, 16, 8, 0, 98, 100, 3, 18, 9, 0, 99, 98, 1, 0, 0, 0, 100, 103, 1, 0, 0, 0, 101, 99, 1, 0, 0, 0, 101, 102, 1, 0, 0, 0, 102, 112, 1, 0, 0, 0, 103, 101, 1, 0, 0, 0, 104, 108, 5, 9, 0, 0, 105, 107, 3, 18, 9, 0, 106, 105, 1, 0, 0, 0, 107, 110, 1, 0, 0, 0, 108, 106, 1, 0, 0, 0, 108, 109, 1, 0, 0, 0, 109, 112, 1, 0, 0, 0, 110, 108, 1, 0, 0, 0, 111, 65, 1, 0, 0, 0, 111, 72, 1, 0, 0, 0, 111, 77, 1, 0, 0, 0, 111, 87, 1, 0, 0, 0, 111, 89, 1, 0, 0, 0, 111, 91, 1, 0, 0, 0, 111, 93, 1, 0, 0, 0, 111, 94, 1, 0, 0, 0, 111, 95, 1, 0, 0, 0, 111, 96, 1, 0, 0, 0, 111, 104, 1, 0, 0, 0, 112, 11, 1, 0, 0, 0, 113, 114, 5, 18, 0, 0, 114, 115, 5, 3, 0, 0, 115, 116, 3, 2, 1, 0, 116, 13, 1, 0, 0, 0, 117, 118, 5, 18, 0, 0, 118, 119, 5, 4, 0, 0, 119, 120, 3, 2, 1, 0, 120, 15, 1, 0, 0, 0, 121, 124, 3, 12, 6, 0, 122, 124, 3, 2, 1, 0, 123, 121, 1, 0, 0, 0, 123, 122, 1, 0, 0, 0, 124, 17, 1, 0, 0, 0, 125, 129, 3, 12, 6, 0, 126, 127, 5, 13, 0, 0, 127, 129, 3, 2, 1, 0, 128, 125, 1, 0, 0, 0, 128, 126, 1, 0, 0, 0, 129, 19, 1, 0, 0, 0, 130, 131, 5, 12, 0, 0, 131, 132, 3, 2, 1, 0, 132, 133, 5, 15, 0, 0, 133, 134, 3, 2, 1, 0, 134, 21, 1, 0, 0, 0, 135, 136, 5, 14, 0, 0, 136, 137, 3, 2, 1, 0, 137, 23, 1, 0, 0, 0, 138, 140, 3, 12, 6, 0, 139, 138, 1, 0, 0, 0, 140, 143, 1, 0, 0, 0, 141, 139, 1, 0, 0, 0, 141, 142, 1, 0, 0, 0, 142, 25, 1, 0, 0, 0, 143, 141, 1, 0, 0, 0, 144, 146, 5, 7, 0, 0, 145, 144, 1, 0, 0, 0, 146, 147, 1, 0, 0, 0, 147, 145, 1, 0, 0, 0, 147, 148, 1, 0, 0, 0, 148, 27, 1, 0, 0, 0, 13, 34, 40, 59, 63, 82, 85, 101, 108, 111, 123, 128, 141, 147]
\ No newline at end of file
+[4, 1, 18, 152, 2, 0, 7, 0, 2, 1, 7, 1, 2, 2, 7, 2, 2, 3, 7, 3, 2, 4, 7, 4, 2, 5, 7, 5, 2, 6, 7, 6, 2, 7, 7, 7, 2, 8, 7, 8, 2, 9, 7, 9, 2, 10, 7, 10, 2, 11, 7, 11, 1, 0, 1, 0, 1, 0, 1, 1, 5, 1, 29, 8, 1, 10, 1, 12, 1, 32, 9, 1, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 3, 2, 46, 8, 2, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 4, 3, 65, 8, 3, 11, 3, 12, 3, 66, 1, 3, 3, 3, 70, 8, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 5, 3, 97, 8, 3, 10, 3, 12, 3, 100, 9, 3, 1, 3, 1, 3, 1, 3, 1, 3, 5, 3, 106, 8, 3, 10, 3, 12, 3, 109, 9, 3, 1, 3, 3, 3, 112, 8, 3, 1, 4, 1, 4, 1, 4, 1, 4, 1, 5, 1, 5, 1, 5, 1, 5, 1, 5, 1, 5, 1, 6, 1, 6, 3, 6, 126, 8, 6, 1, 7, 1, 7, 1, 7, 3, 7, 131, 8, 7, 1, 8, 1, 8, 1, 8, 1, 8, 1, 8, 1, 9, 1, 9, 1, 9, 1, 10, 5, 10, 142, 8, 10, 10, 10, 12, 10, 145, 9, 10, 1, 11, 4, 11, 148, 8, 11, 11, 11, 12, 11, 149, 1, 11, 1, 30, 0, 12, 0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 0, 0, 169, 0, 24, 1, 0, 0, 0, 2, 30, 1, 0, 0, 0, 4, 45, 1, 0, 0, 0, 6, 111, 1, 0, 0, 0, 8, 113, 1, 0, 0, 0, 10, 117, 1, 0, 0, 0, 12, 125, 1, 0, 0, 0, 14, 130, 1, 0, 0, 0, 16, 132, 1, 0, 0, 0, 18, 137, 1, 0, 0, 0, 20, 143, 1, 0, 0, 0, 22, 147, 1, 0, 0, 0, 24, 25, 3, 2, 1, 0, 25, 26, 5, 0, 0, 1, 26, 1, 1, 0, 0, 0, 27, 29, 3, 4, 2, 0, 28, 27, 1, 0, 0, 0, 29, 32, 1, 0, 0, 0, 30, 31, 1, 0, 0, 0, 30, 28, 1, 0, 0, 0, 31, 3, 1, 0, 0, 0, 32, 30, 1, 0, 0, 0, 33, 46, 3, 6, 3, 0, 34, 46, 3, 22, 11, 0, 35, 46, 5, 6, 0, 0, 36, 46, 5, 5, 0, 0, 37, 46, 5, 3, 0, 0, 38, 46, 5, 18, 0, 0, 39, 46, 5, 11, 0, 0, 40, 46, 5, 12, 0, 0, 41, 46, 5, 14, 0, 0, 42, 46, 5, 15, 0, 0, 43, 46, 5, 9, 0, 0, 44, 46, 5, 13, 0, 0, 45, 33, 1, 0, 0, 0, 45, 34, 1, 0, 0, 0, 45, 35, 1, 0, 0, 0, 45, 36, 1, 0, 0, 0, 45, 37, 1, 0, 0, 0, 45, 38, 1, 0, 0, 0, 45, 39, 1, 0, 0, 0, 45, 40, 1, 0, 0, 0, 45, 41, 1, 0, 0, 0, 45, 42, 1, 0, 0, 0, 45, 43, 1, 0, 0, 0, 45, 44, 1, 0, 0, 0, 46, 5, 1, 0, 0, 0, 47, 48, 5, 10, 0, 0, 48, 49, 3, 2, 1, 0, 49, 50, 5, 16, 0, 0, 50, 51, 3, 2, 1, 0, 51, 52, 5, 17, 0, 0, 52, 53, 3, 2, 1, 0, 53, 54, 5, 2, 0, 0, 54, 112, 1, 0, 0, 0, 55, 56, 5, 10, 0, 0, 56, 57, 3, 2, 1, 0, 57, 58, 5, 16, 0, 0, 58, 59, 3, 2, 1, 0, 59, 60, 5, 2, 0, 0, 60, 112, 1, 0, 0, 0, 61, 62, 5, 11, 0, 0, 62, 64, 3, 2, 1, 0, 63, 65, 3, 16, 8, 0, 64, 63, 1, 0, 0, 0, 65, 66, 1, 0, 0, 0, 66, 64, 1, 0, 0, 0, 66, 67, 1, 0, 0, 0, 67, 69, 1, 0, 0, 0, 68, 70, 3, 18, 9, 0, 69, 68, 1, 0, 0, 0, 69, 70, 1, 0, 0, 0, 70, 71, 1, 0, 0, 0, 71, 72, 5, 2, 0, 0, 72, 112, 1, 0, 0, 0, 73, 74, 5, 8, 0, 0, 74, 75, 3, 20, 10, 0, 75, 76, 5, 2, 0, 0, 76, 112, 1, 0, 0, 0, 77, 78, 5, 5, 0, 0, 78, 79, 3, 2, 1, 0, 79, 80, 5, 2, 0, 0, 80, 112, 1, 0, 0, 0, 81, 82, 5, 6, 0, 0, 82, 83, 3, 2, 1, 0, 83, 84, 5, 2, 0, 0, 84, 112, 1, 0, 0, 0, 85, 86, 5, 1, 0, 0, 86, 87, 3, 8, 4, 0, 87, 88, 5, 2, 0, 0, 88, 112, 1, 0, 0, 0, 89, 112, 3, 10, 5, 0, 90, 91, 5, 1, 0, 0, 91, 92, 5, 18, 0, 0, 92, 112, 5, 2, 0, 0, 93, 94, 5, 9, 0, 0, 94, 98, 3, 12, 6, 0, 95, 97, 3, 14, 7, 0, 96, 95, 1, 0, 0, 0, 97, 100, 1, 0, 0, 0, 98, 96, 1, 0, 0, 0, 98, 99, 1, 0, 0, 0, 99, 101, 1, 0, 0, 0, 100, 98, 1, 0, 0, 0, 101, 102, 5, 2, 0, 0, 102, 112, 1, 0, 0, 0, 103, 107, 5, 9, 0, 0, 104, 106, 3, 14, 7, 0, 105, 104, 1, 0, 0, 0, 106, 109, 1, 0, 0, 0, 107, 105, 1, 0, 0, 0, 107, 108, 1, 0, 0, 0, 108, 110, 1, 0, 0, 0, 109, 107, 1, 0, 0, 0, 110, 112, 5, 2, 0, 0, 111, 47, 1, 0, 0, 0, 111, 55, 1, 0, 0, 0, 111, 61, 1, 0, 0, 0, 111, 73, 1, 0, 0, 0, 111, 77, 1, 0, 0, 0, 111, 81, 1, 0, 0, 0, 111, 85, 1, 0, 0, 0, 111, 89, 1, 0, 0, 0, 111, 90, 1, 0, 0, 0, 111, 93, 1, 0, 0, 0, 111, 103, 1, 0, 0, 0, 112, 7, 1, 0, 0, 0, 113, 114, 5, 18, 0, 0, 114, 115, 5, 3, 0, 0, 115, 116, 3, 2, 1, 0, 116, 9, 1, 0, 0, 0, 117, 118, 5, 1, 0, 0, 118, 119, 5, 18, 0, 0, 119, 120, 5, 4, 0, 0, 120, 121, 3, 2, 1, 0, 121, 122, 5, 2, 0, 0, 122, 11, 1, 0, 0, 0, 123, 126, 3, 8, 4, 0, 124, 126, 3, 2, 1, 0, 125, 123, 1, 0, 0, 0, 125, 124, 1, 0, 0, 0, 126, 13, 1, 0, 0, 0, 127, 131, 3, 8, 4, 0, 128, 129, 5, 13, 0, 0, 129, 131, 3, 2, 1, 0, 130, 127, 1, 0, 0, 0, 130, 128, 1, 0, 0, 0, 131, 15, 1, 0, 0, 0, 132, 133, 5, 12, 0, 0, 133, 134, 3, 2, 1, 0, 134, 135, 5, 15, 0, 0, 135, 136, 3, 2, 1, 0, 136, 17, 1, 0, 0, 0, 137, 138, 5, 14, 0, 0, 138, 139, 3, 2, 1, 0, 139, 19, 1, 0, 0, 0, 140, 142, 3, 8, 4, 0, 141, 140, 1, 0, 0, 0, 142, 145, 1, 0, 0, 0, 143, 141, 1, 0, 0, 0, 143, 144, 1, 0, 0, 0, 144, 21, 1, 0, 0, 0, 145, 143, 1, 0, 0, 0, 146, 148, 5, 7, 0, 0, 147, 146, 1, 0, 0, 0, 148, 149, 1, 0, 0, 0, 149, 147, 1, 0, 0, 0, 149, 150, 1, 0, 0, 0, 150, 23, 1, 0, 0, 0, 11, 30, 45, 66, 69, 98, 107, 111, 125, 130, 143, 149]
\ No newline at end of file
diff --git a/python/src/parser/MetaPrompt.tokens b/python/src/parser/MetaPrompt.tokens
index 8e644ab..b738699 100644
--- a/python/src/parser/MetaPrompt.tokens
+++ b/python/src/parser/MetaPrompt.tokens
@@ -20,9 +20,6 @@ VAR_NAME=18
 ']'=2
 '='=3
 '?='=4
-'#'=6
-':if'=10
-':choose'=11
 ':option'=12
 ':with'=13
 ':default'=14
diff --git a/python/src/parser/MetaPromptLexer.interp b/python/src/parser/MetaPromptLexer.interp
index 4e87365..eecaf35 100644
--- a/python/src/parser/MetaPromptLexer.interp
+++ b/python/src/parser/MetaPromptLexer.interp
@@ -5,12 +5,12 @@ null
 '='
 '?='
 null
-'#'
 null
 null
 null
-':if'
-':choose'
+null
+null
+null
 ':option'
 ':with'
 ':default'
@@ -72,4 +72,4 @@ mode names:
 DEFAULT_MODE
 
 atn:
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\ No newline at end of file
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\ No newline at end of file
diff --git a/python/src/parser/MetaPromptLexer.py b/python/src/parser/MetaPromptLexer.py
index 35069a3..fedb671 100644
--- a/python/src/parser/MetaPromptLexer.py
+++ b/python/src/parser/MetaPromptLexer.py
@@ -10,67 +10,70 @@
 
 def serializedATN():
     return [
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+        78,1,0,0,0,80,18,1,0,0,0,81,82,5,92,0,0,82,20,1,0,0,0,83,84,3,1,
+        0,0,84,85,5,58,0,0,85,86,5,117,0,0,86,87,5,115,0,0,87,88,5,101,0,
+        0,88,90,1,0,0,0,89,91,3,25,12,0,90,89,1,0,0,0,91,92,1,0,0,0,92,90,
+        1,0,0,0,92,93,1,0,0,0,93,95,1,0,0,0,94,96,7,2,0,0,95,94,1,0,0,0,
+        96,97,1,0,0,0,97,95,1,0,0,0,97,98,1,0,0,0,98,102,1,0,0,0,99,101,
+        3,25,12,0,100,99,1,0,0,0,101,104,1,0,0,0,102,100,1,0,0,0,102,103,
+        1,0,0,0,103,22,1,0,0,0,104,102,1,0,0,0,105,106,3,1,0,0,106,107,5,
+        64,0,0,107,111,7,0,0,0,108,110,7,1,0,0,109,108,1,0,0,0,110,113,1,
+        0,0,0,111,109,1,0,0,0,111,112,1,0,0,0,112,117,1,0,0,0,113,111,1,
+        0,0,0,114,116,3,25,12,0,115,114,1,0,0,0,116,119,1,0,0,0,117,115,
+        1,0,0,0,117,118,1,0,0,0,118,24,1,0,0,0,119,117,1,0,0,0,120,121,7,
+        3,0,0,121,26,1,0,0,0,122,123,3,1,0,0,123,124,5,58,0,0,124,125,5,
+        105,0,0,125,126,5,102,0,0,126,28,1,0,0,0,127,128,3,1,0,0,128,129,
+        5,58,0,0,129,130,5,99,0,0,130,131,5,104,0,0,131,132,5,111,0,0,132,
+        133,5,111,0,0,133,134,5,115,0,0,134,135,5,101,0,0,135,30,1,0,0,0,
+        136,137,5,58,0,0,137,138,5,111,0,0,138,139,5,112,0,0,139,140,5,116,
+        0,0,140,141,5,105,0,0,141,142,5,111,0,0,142,143,5,110,0,0,143,32,
+        1,0,0,0,144,145,5,58,0,0,145,146,5,119,0,0,146,147,5,105,0,0,147,
+        148,5,116,0,0,148,149,5,104,0,0,149,34,1,0,0,0,150,151,5,58,0,0,
+        151,152,5,100,0,0,152,153,5,101,0,0,153,154,5,102,0,0,154,155,5,
+        97,0,0,155,156,5,117,0,0,156,157,5,108,0,0,157,158,5,116,0,0,158,
+        36,1,0,0,0,159,160,5,58,0,0,160,161,5,105,0,0,161,162,5,115,0,0,
+        162,38,1,0,0,0,163,164,5,58,0,0,164,165,5,116,0,0,165,166,5,104,
+        0,0,166,167,5,101,0,0,167,168,5,110,0,0,168,40,1,0,0,0,169,170,5,
+        58,0,0,170,171,5,101,0,0,171,172,5,108,0,0,172,173,5,115,0,0,173,
+        174,5,101,0,0,174,42,1,0,0,0,175,176,5,58,0,0,176,180,7,0,0,0,177,
+        179,7,1,0,0,178,177,1,0,0,0,179,182,1,0,0,0,180,178,1,0,0,0,180,
+        181,1,0,0,0,181,44,1,0,0,0,182,180,1,0,0,0,11,0,56,61,71,79,92,97,
+        102,111,117,180,0
     ]
 
 class MetaPromptLexer(Lexer):
@@ -103,8 +106,8 @@ class MetaPromptLexer(Lexer):
     modeNames = [ "DEFAULT_MODE" ]
 
     literalNames = [ "<INVALID>",
-            "'['", "']'", "'='", "'?='", "'#'", "':if'", "':choose'", "':option'", 
-            "':with'", "':default'", "':is'", "':then'", "':else'" ]
+            "'['", "']'", "'='", "'?='", "':option'", "':with'", "':default'", 
+            "':is'", "':then'", "':else'" ]
 
     symbolicNames = [ "<INVALID>",
             "LB", "RB", "EQ_KW", "EQ_OPTIONAL_KW", "META_PROMPT", "COMMENT_KW", 
diff --git a/python/src/parser/MetaPromptLexer.tokens b/python/src/parser/MetaPromptLexer.tokens
index 8e644ab..b738699 100644
--- a/python/src/parser/MetaPromptLexer.tokens
+++ b/python/src/parser/MetaPromptLexer.tokens
@@ -20,9 +20,6 @@ VAR_NAME=18
 ']'=2
 '='=3
 '?='=4
-'#'=6
-':if'=10
-':choose'=11
 ':option'=12
 ':with'=13
 ':default'=14
diff --git a/python/src/parser/MetaPromptListener.py b/python/src/parser/MetaPromptListener.py
index 1a9c8d4..6340d1e 100644
--- a/python/src/parser/MetaPromptListener.py
+++ b/python/src/parser/MetaPromptListener.py
@@ -26,15 +26,6 @@ def exitExprs(self, ctx:MetaPromptParser.ExprsContext):
         pass
 
 
-    # Enter a parse tree produced by MetaPromptParser#exprs1.
-    def enterExprs1(self, ctx:MetaPromptParser.Exprs1Context):
-        pass
-
-    # Exit a parse tree produced by MetaPromptParser#exprs1.
-    def exitExprs1(self, ctx:MetaPromptParser.Exprs1Context):
-        pass
-
-
     # Enter a parse tree produced by MetaPromptParser#expr.
     def enterExpr(self, ctx:MetaPromptParser.ExprContext):
         pass
@@ -44,15 +35,6 @@ def exitExpr(self, ctx:MetaPromptParser.ExprContext):
         pass
 
 
-    # Enter a parse tree produced by MetaPromptParser#expr1.
-    def enterExpr1(self, ctx:MetaPromptParser.Expr1Context):
-        pass
-
-    # Exit a parse tree produced by MetaPromptParser#expr1.
-    def exitExpr1(self, ctx:MetaPromptParser.Expr1Context):
-        pass
-
-
     # Enter a parse tree produced by MetaPromptParser#meta_body.
     def enterMeta_body(self, ctx:MetaPromptParser.Meta_bodyContext):
         pass
diff --git a/python/src/parser/MetaPromptParser.py b/python/src/parser/MetaPromptParser.py
index 96644a3..6bb9bc0 100644
--- a/python/src/parser/MetaPromptParser.py
+++ b/python/src/parser/MetaPromptParser.py
@@ -10,58 +10,58 @@
 
 def serializedATN():
     return [
-        4,1,18,150,2,0,7,0,2,1,7,1,2,2,7,2,2,3,7,3,2,4,7,4,2,5,7,5,2,6,7,
-        6,2,7,7,7,2,8,7,8,2,9,7,9,2,10,7,10,2,11,7,11,2,12,7,12,2,13,7,13,
-        1,0,1,0,1,0,1,1,5,1,33,8,1,10,1,12,1,36,9,1,1,2,4,2,39,8,2,11,2,
-        12,2,40,1,3,1,3,1,3,1,3,1,3,1,3,1,3,1,3,1,3,1,3,1,3,1,3,1,3,1,3,
-        1,3,1,3,1,3,3,3,60,8,3,1,4,1,4,3,4,64,8,4,1,5,1,5,1,5,1,5,1,5,1,
-        5,1,5,1,5,1,5,1,5,1,5,1,5,1,5,1,5,1,5,4,5,81,8,5,11,5,12,5,82,1,
-        5,3,5,86,8,5,1,5,1,5,1,5,1,5,1,5,1,5,1,5,1,5,1,5,1,5,1,5,1,5,5,5,
-        100,8,5,10,5,12,5,103,9,5,1,5,1,5,5,5,107,8,5,10,5,12,5,110,9,5,
-        3,5,112,8,5,1,6,1,6,1,6,1,6,1,7,1,7,1,7,1,7,1,8,1,8,3,8,124,8,8,
-        1,9,1,9,1,9,3,9,129,8,9,1,10,1,10,1,10,1,10,1,10,1,11,1,11,1,11,
-        1,12,5,12,140,8,12,10,12,12,12,143,9,12,1,13,4,13,146,8,13,11,13,
-        12,13,147,1,13,2,34,40,0,14,0,2,4,6,8,10,12,14,16,18,20,22,24,26,
-        0,0,169,0,28,1,0,0,0,2,34,1,0,0,0,4,38,1,0,0,0,6,59,1,0,0,0,8,63,
-        1,0,0,0,10,111,1,0,0,0,12,113,1,0,0,0,14,117,1,0,0,0,16,123,1,0,
-        0,0,18,128,1,0,0,0,20,130,1,0,0,0,22,135,1,0,0,0,24,141,1,0,0,0,
-        26,145,1,0,0,0,28,29,3,2,1,0,29,30,5,0,0,1,30,1,1,0,0,0,31,33,3,
-        6,3,0,32,31,1,0,0,0,33,36,1,0,0,0,34,35,1,0,0,0,34,32,1,0,0,0,35,
-        3,1,0,0,0,36,34,1,0,0,0,37,39,3,6,3,0,38,37,1,0,0,0,39,40,1,0,0,
-        0,40,41,1,0,0,0,40,38,1,0,0,0,41,5,1,0,0,0,42,43,5,1,0,0,43,44,3,
-        8,4,0,44,45,5,2,0,0,45,60,1,0,0,0,46,60,3,26,13,0,47,60,5,2,0,0,
-        48,60,5,1,0,0,49,60,5,6,0,0,50,60,5,5,0,0,51,60,5,3,0,0,52,60,5,
-        18,0,0,53,60,5,11,0,0,54,60,5,12,0,0,55,60,5,14,0,0,56,60,5,15,0,
-        0,57,60,5,9,0,0,58,60,5,13,0,0,59,42,1,0,0,0,59,46,1,0,0,0,59,47,
-        1,0,0,0,59,48,1,0,0,0,59,49,1,0,0,0,59,50,1,0,0,0,59,51,1,0,0,0,
-        59,52,1,0,0,0,59,53,1,0,0,0,59,54,1,0,0,0,59,55,1,0,0,0,59,56,1,
-        0,0,0,59,57,1,0,0,0,59,58,1,0,0,0,60,7,1,0,0,0,61,64,3,10,5,0,62,
-        64,3,2,1,0,63,61,1,0,0,0,63,62,1,0,0,0,64,9,1,0,0,0,65,66,5,10,0,
-        0,66,67,3,2,1,0,67,68,5,16,0,0,68,69,3,2,1,0,69,70,5,17,0,0,70,71,
-        3,2,1,0,71,112,1,0,0,0,72,73,5,10,0,0,73,74,3,2,1,0,74,75,5,16,0,
-        0,75,76,3,2,1,0,76,112,1,0,0,0,77,78,5,11,0,0,78,80,3,2,1,0,79,81,
-        3,20,10,0,80,79,1,0,0,0,81,82,1,0,0,0,82,80,1,0,0,0,82,83,1,0,0,
-        0,83,85,1,0,0,0,84,86,3,22,11,0,85,84,1,0,0,0,85,86,1,0,0,0,86,112,
-        1,0,0,0,87,88,5,8,0,0,88,112,3,24,12,0,89,90,5,5,0,0,90,112,3,2,
-        1,0,91,92,5,6,0,0,92,112,3,2,1,0,93,112,3,12,6,0,94,112,3,14,7,0,
-        95,112,5,18,0,0,96,97,5,9,0,0,97,101,3,16,8,0,98,100,3,18,9,0,99,
-        98,1,0,0,0,100,103,1,0,0,0,101,99,1,0,0,0,101,102,1,0,0,0,102,112,
-        1,0,0,0,103,101,1,0,0,0,104,108,5,9,0,0,105,107,3,18,9,0,106,105,
-        1,0,0,0,107,110,1,0,0,0,108,106,1,0,0,0,108,109,1,0,0,0,109,112,
-        1,0,0,0,110,108,1,0,0,0,111,65,1,0,0,0,111,72,1,0,0,0,111,77,1,0,
-        0,0,111,87,1,0,0,0,111,89,1,0,0,0,111,91,1,0,0,0,111,93,1,0,0,0,
-        111,94,1,0,0,0,111,95,1,0,0,0,111,96,1,0,0,0,111,104,1,0,0,0,112,
-        11,1,0,0,0,113,114,5,18,0,0,114,115,5,3,0,0,115,116,3,2,1,0,116,
-        13,1,0,0,0,117,118,5,18,0,0,118,119,5,4,0,0,119,120,3,2,1,0,120,
-        15,1,0,0,0,121,124,3,12,6,0,122,124,3,2,1,0,123,121,1,0,0,0,123,
-        122,1,0,0,0,124,17,1,0,0,0,125,129,3,12,6,0,126,127,5,13,0,0,127,
-        129,3,2,1,0,128,125,1,0,0,0,128,126,1,0,0,0,129,19,1,0,0,0,130,131,
-        5,12,0,0,131,132,3,2,1,0,132,133,5,15,0,0,133,134,3,2,1,0,134,21,
-        1,0,0,0,135,136,5,14,0,0,136,137,3,2,1,0,137,23,1,0,0,0,138,140,
-        3,12,6,0,139,138,1,0,0,0,140,143,1,0,0,0,141,139,1,0,0,0,141,142,
-        1,0,0,0,142,25,1,0,0,0,143,141,1,0,0,0,144,146,5,7,0,0,145,144,1,
-        0,0,0,146,147,1,0,0,0,147,145,1,0,0,0,147,148,1,0,0,0,148,27,1,0,
-        0,0,13,34,40,59,63,82,85,101,108,111,123,128,141,147
+        4,1,18,152,2,0,7,0,2,1,7,1,2,2,7,2,2,3,7,3,2,4,7,4,2,5,7,5,2,6,7,
+        6,2,7,7,7,2,8,7,8,2,9,7,9,2,10,7,10,2,11,7,11,1,0,1,0,1,0,1,1,5,
+        1,29,8,1,10,1,12,1,32,9,1,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,
+        2,1,2,1,2,3,2,46,8,2,1,3,1,3,1,3,1,3,1,3,1,3,1,3,1,3,1,3,1,3,1,3,
+        1,3,1,3,1,3,1,3,1,3,1,3,4,3,65,8,3,11,3,12,3,66,1,3,3,3,70,8,3,1,
+        3,1,3,1,3,1,3,1,3,1,3,1,3,1,3,1,3,1,3,1,3,1,3,1,3,1,3,1,3,1,3,1,
+        3,1,3,1,3,1,3,1,3,1,3,1,3,1,3,1,3,5,3,97,8,3,10,3,12,3,100,9,3,1,
+        3,1,3,1,3,1,3,5,3,106,8,3,10,3,12,3,109,9,3,1,3,3,3,112,8,3,1,4,
+        1,4,1,4,1,4,1,5,1,5,1,5,1,5,1,5,1,5,1,6,1,6,3,6,126,8,6,1,7,1,7,
+        1,7,3,7,131,8,7,1,8,1,8,1,8,1,8,1,8,1,9,1,9,1,9,1,10,5,10,142,8,
+        10,10,10,12,10,145,9,10,1,11,4,11,148,8,11,11,11,12,11,149,1,11,
+        1,30,0,12,0,2,4,6,8,10,12,14,16,18,20,22,0,0,169,0,24,1,0,0,0,2,
+        30,1,0,0,0,4,45,1,0,0,0,6,111,1,0,0,0,8,113,1,0,0,0,10,117,1,0,0,
+        0,12,125,1,0,0,0,14,130,1,0,0,0,16,132,1,0,0,0,18,137,1,0,0,0,20,
+        143,1,0,0,0,22,147,1,0,0,0,24,25,3,2,1,0,25,26,5,0,0,1,26,1,1,0,
+        0,0,27,29,3,4,2,0,28,27,1,0,0,0,29,32,1,0,0,0,30,31,1,0,0,0,30,28,
+        1,0,0,0,31,3,1,0,0,0,32,30,1,0,0,0,33,46,3,6,3,0,34,46,3,22,11,0,
+        35,46,5,6,0,0,36,46,5,5,0,0,37,46,5,3,0,0,38,46,5,18,0,0,39,46,5,
+        11,0,0,40,46,5,12,0,0,41,46,5,14,0,0,42,46,5,15,0,0,43,46,5,9,0,
+        0,44,46,5,13,0,0,45,33,1,0,0,0,45,34,1,0,0,0,45,35,1,0,0,0,45,36,
+        1,0,0,0,45,37,1,0,0,0,45,38,1,0,0,0,45,39,1,0,0,0,45,40,1,0,0,0,
+        45,41,1,0,0,0,45,42,1,0,0,0,45,43,1,0,0,0,45,44,1,0,0,0,46,5,1,0,
+        0,0,47,48,5,10,0,0,48,49,3,2,1,0,49,50,5,16,0,0,50,51,3,2,1,0,51,
+        52,5,17,0,0,52,53,3,2,1,0,53,54,5,2,0,0,54,112,1,0,0,0,55,56,5,10,
+        0,0,56,57,3,2,1,0,57,58,5,16,0,0,58,59,3,2,1,0,59,60,5,2,0,0,60,
+        112,1,0,0,0,61,62,5,11,0,0,62,64,3,2,1,0,63,65,3,16,8,0,64,63,1,
+        0,0,0,65,66,1,0,0,0,66,64,1,0,0,0,66,67,1,0,0,0,67,69,1,0,0,0,68,
+        70,3,18,9,0,69,68,1,0,0,0,69,70,1,0,0,0,70,71,1,0,0,0,71,72,5,2,
+        0,0,72,112,1,0,0,0,73,74,5,8,0,0,74,75,3,20,10,0,75,76,5,2,0,0,76,
+        112,1,0,0,0,77,78,5,5,0,0,78,79,3,2,1,0,79,80,5,2,0,0,80,112,1,0,
+        0,0,81,82,5,6,0,0,82,83,3,2,1,0,83,84,5,2,0,0,84,112,1,0,0,0,85,
+        86,5,1,0,0,86,87,3,8,4,0,87,88,5,2,0,0,88,112,1,0,0,0,89,112,3,10,
+        5,0,90,91,5,1,0,0,91,92,5,18,0,0,92,112,5,2,0,0,93,94,5,9,0,0,94,
+        98,3,12,6,0,95,97,3,14,7,0,96,95,1,0,0,0,97,100,1,0,0,0,98,96,1,
+        0,0,0,98,99,1,0,0,0,99,101,1,0,0,0,100,98,1,0,0,0,101,102,5,2,0,
+        0,102,112,1,0,0,0,103,107,5,9,0,0,104,106,3,14,7,0,105,104,1,0,0,
+        0,106,109,1,0,0,0,107,105,1,0,0,0,107,108,1,0,0,0,108,110,1,0,0,
+        0,109,107,1,0,0,0,110,112,5,2,0,0,111,47,1,0,0,0,111,55,1,0,0,0,
+        111,61,1,0,0,0,111,73,1,0,0,0,111,77,1,0,0,0,111,81,1,0,0,0,111,
+        85,1,0,0,0,111,89,1,0,0,0,111,90,1,0,0,0,111,93,1,0,0,0,111,103,
+        1,0,0,0,112,7,1,0,0,0,113,114,5,18,0,0,114,115,5,3,0,0,115,116,3,
+        2,1,0,116,9,1,0,0,0,117,118,5,1,0,0,118,119,5,18,0,0,119,120,5,4,
+        0,0,120,121,3,2,1,0,121,122,5,2,0,0,122,11,1,0,0,0,123,126,3,8,4,
+        0,124,126,3,2,1,0,125,123,1,0,0,0,125,124,1,0,0,0,126,13,1,0,0,0,
+        127,131,3,8,4,0,128,129,5,13,0,0,129,131,3,2,1,0,130,127,1,0,0,0,
+        130,128,1,0,0,0,131,15,1,0,0,0,132,133,5,12,0,0,133,134,3,2,1,0,
+        134,135,5,15,0,0,135,136,3,2,1,0,136,17,1,0,0,0,137,138,5,14,0,0,
+        138,139,3,2,1,0,139,19,1,0,0,0,140,142,3,8,4,0,141,140,1,0,0,0,142,
+        145,1,0,0,0,143,141,1,0,0,0,143,144,1,0,0,0,144,21,1,0,0,0,145,143,
+        1,0,0,0,146,148,5,7,0,0,147,146,1,0,0,0,148,149,1,0,0,0,149,147,
+        1,0,0,0,149,150,1,0,0,0,150,23,1,0,0,0,11,30,45,66,69,98,107,111,
+        125,130,143,149
     ]
 
 class MetaPromptParser ( Parser ):
@@ -75,8 +75,8 @@ class MetaPromptParser ( Parser ):
     sharedContextCache = PredictionContextCache()
 
     literalNames = [ "<INVALID>", "'['", "']'", "'='", "'?='", "<INVALID>", 
-                     "'#'", "<INVALID>", "<INVALID>", "<INVALID>", "':if'", 
-                     "':choose'", "':option'", "':with'", "':default'", 
+                     "<INVALID>", "<INVALID>", "<INVALID>", "<INVALID>", 
+                     "<INVALID>", "<INVALID>", "':option'", "':with'", "':default'", 
                      "':is'", "':then'", "':else'" ]
 
     symbolicNames = [ "<INVALID>", "LB", "RB", "EQ_KW", "EQ_OPTIONAL_KW", 
@@ -86,23 +86,20 @@ class MetaPromptParser ( Parser ):
 
     RULE_prompt = 0
     RULE_exprs = 1
-    RULE_exprs1 = 2
-    RULE_expr = 3
-    RULE_expr1 = 4
-    RULE_meta_body = 5
-    RULE_var_assignment = 6
-    RULE_var_optional_assignment = 7
-    RULE_call_arg1 = 8
-    RULE_call_arg = 9
-    RULE_option = 10
-    RULE_default_option = 11
-    RULE_named_parameters = 12
-    RULE_text = 13
-
-    ruleNames =  [ "prompt", "exprs", "exprs1", "expr", "expr1", "meta_body", 
-                   "var_assignment", "var_optional_assignment", "call_arg1", 
-                   "call_arg", "option", "default_option", "named_parameters", 
-                   "text" ]
+    RULE_expr = 2
+    RULE_meta_body = 3
+    RULE_var_assignment = 4
+    RULE_var_optional_assignment = 5
+    RULE_call_arg1 = 6
+    RULE_call_arg = 7
+    RULE_option = 8
+    RULE_default_option = 9
+    RULE_named_parameters = 10
+    RULE_text = 11
+
+    ruleNames =  [ "prompt", "exprs", "expr", "meta_body", "var_assignment", 
+                   "var_optional_assignment", "call_arg1", "call_arg", "option", 
+                   "default_option", "named_parameters", "text" ]
 
     EOF = Token.EOF
     LB=1
@@ -173,9 +170,9 @@ def prompt(self):
         self.enterRule(localctx, 0, self.RULE_prompt)
         try:
             self.enterOuterAlt(localctx, 1)
-            self.state = 28
+            self.state = 24
             self.exprs()
-            self.state = 29
+            self.state = 25
             self.match(MetaPromptParser.EOF)
         except RecognitionException as re:
             localctx.exception = re
@@ -226,14 +223,14 @@ def exprs(self):
         self.enterRule(localctx, 2, self.RULE_exprs)
         try:
             self.enterOuterAlt(localctx, 1)
-            self.state = 34
+            self.state = 30
             self._errHandler.sync(self)
             _alt = self._interp.adaptivePredict(self._input,0,self._ctx)
             while _alt!=1 and _alt!=ATN.INVALID_ALT_NUMBER:
                 if _alt==1+1:
-                    self.state = 31
+                    self.state = 27
                     self.expr() 
-                self.state = 36
+                self.state = 32
                 self._errHandler.sync(self)
                 _alt = self._interp.adaptivePredict(self._input,0,self._ctx)
 
@@ -246,69 +243,6 @@ def exprs(self):
         return localctx
 
 
-    class Exprs1Context(ParserRuleContext):
-        __slots__ = 'parser'
-
-        def __init__(self, parser, parent:ParserRuleContext=None, invokingState:int=-1):
-            super().__init__(parent, invokingState)
-            self.parser = parser
-
-        def expr(self, i:int=None):
-            if i is None:
-                return self.getTypedRuleContexts(MetaPromptParser.ExprContext)
-            else:
-                return self.getTypedRuleContext(MetaPromptParser.ExprContext,i)
-
-
-        def getRuleIndex(self):
-            return MetaPromptParser.RULE_exprs1
-
-        def enterRule(self, listener:ParseTreeListener):
-            if hasattr( listener, "enterExprs1" ):
-                listener.enterExprs1(self)
-
-        def exitRule(self, listener:ParseTreeListener):
-            if hasattr( listener, "exitExprs1" ):
-                listener.exitExprs1(self)
-
-        def accept(self, visitor:ParseTreeVisitor):
-            if hasattr( visitor, "visitExprs1" ):
-                return visitor.visitExprs1(self)
-            else:
-                return visitor.visitChildren(self)
-
-
-
-
-    def exprs1(self):
-
-        localctx = MetaPromptParser.Exprs1Context(self, self._ctx, self.state)
-        self.enterRule(localctx, 4, self.RULE_exprs1)
-        try:
-            self.enterOuterAlt(localctx, 1)
-            self.state = 38 
-            self._errHandler.sync(self)
-            _alt = 1+1
-            while _alt!=1 and _alt!=ATN.INVALID_ALT_NUMBER:
-                if _alt == 1+1:
-                    self.state = 37
-                    self.expr()
-
-                else:
-                    raise NoViableAltException(self)
-                self.state = 40 
-                self._errHandler.sync(self)
-                _alt = self._interp.adaptivePredict(self._input,1,self._ctx)
-
-        except RecognitionException as re:
-            localctx.exception = re
-            self._errHandler.reportError(self, re)
-            self._errHandler.recover(self, re)
-        finally:
-            self.exitRule()
-        return localctx
-
-
     class ExprContext(ParserRuleContext):
         __slots__ = 'parser'
 
@@ -316,15 +250,9 @@ def __init__(self, parser, parent:ParserRuleContext=None, invokingState:int=-1):
             super().__init__(parent, invokingState)
             self.parser = parser
 
-        def LB(self):
-            return self.getToken(MetaPromptParser.LB, 0)
-
-        def expr1(self):
-            return self.getTypedRuleContext(MetaPromptParser.Expr1Context,0)
-
+        def meta_body(self):
+            return self.getTypedRuleContext(MetaPromptParser.Meta_bodyContext,0)
 
-        def RB(self):
-            return self.getToken(MetaPromptParser.RB, 0)
 
         def text(self):
             return self.getTypedRuleContext(MetaPromptParser.TextContext,0)
@@ -383,96 +311,80 @@ def accept(self, visitor:ParseTreeVisitor):
     def expr(self):
 
         localctx = MetaPromptParser.ExprContext(self, self._ctx, self.state)
-        self.enterRule(localctx, 6, self.RULE_expr)
+        self.enterRule(localctx, 4, self.RULE_expr)
         try:
-            self.state = 59
+            self.state = 45
             self._errHandler.sync(self)
-            la_ = self._interp.adaptivePredict(self._input,2,self._ctx)
+            la_ = self._interp.adaptivePredict(self._input,1,self._ctx)
             if la_ == 1:
                 self.enterOuterAlt(localctx, 1)
-                self.state = 42
-                self.match(MetaPromptParser.LB)
-                self.state = 43
-                self.expr1()
-                self.state = 44
-                self.match(MetaPromptParser.RB)
+                self.state = 33
+                self.meta_body()
                 pass
 
             elif la_ == 2:
                 self.enterOuterAlt(localctx, 2)
-                self.state = 46
+                self.state = 34
                 self.text()
                 pass
 
             elif la_ == 3:
                 self.enterOuterAlt(localctx, 3)
-                self.state = 47
-                self.match(MetaPromptParser.RB)
+                self.state = 35
+                self.match(MetaPromptParser.COMMENT_KW)
                 pass
 
             elif la_ == 4:
                 self.enterOuterAlt(localctx, 4)
-                self.state = 48
-                self.match(MetaPromptParser.LB)
+                self.state = 36
+                self.match(MetaPromptParser.META_PROMPT)
                 pass
 
             elif la_ == 5:
                 self.enterOuterAlt(localctx, 5)
-                self.state = 49
-                self.match(MetaPromptParser.COMMENT_KW)
+                self.state = 37
+                self.match(MetaPromptParser.EQ_KW)
                 pass
 
             elif la_ == 6:
                 self.enterOuterAlt(localctx, 6)
-                self.state = 50
-                self.match(MetaPromptParser.META_PROMPT)
+                self.state = 38
+                self.match(MetaPromptParser.VAR_NAME)
                 pass
 
             elif la_ == 7:
                 self.enterOuterAlt(localctx, 7)
-                self.state = 51
-                self.match(MetaPromptParser.EQ_KW)
+                self.state = 39
+                self.match(MetaPromptParser.CHOOSE_KW)
                 pass
 
             elif la_ == 8:
                 self.enterOuterAlt(localctx, 8)
-                self.state = 52
-                self.match(MetaPromptParser.VAR_NAME)
+                self.state = 40
+                self.match(MetaPromptParser.OPTION_KW)
                 pass
 
             elif la_ == 9:
                 self.enterOuterAlt(localctx, 9)
-                self.state = 53
-                self.match(MetaPromptParser.CHOOSE_KW)
+                self.state = 41
+                self.match(MetaPromptParser.DEFAULT_KW)
                 pass
 
             elif la_ == 10:
                 self.enterOuterAlt(localctx, 10)
-                self.state = 54
-                self.match(MetaPromptParser.OPTION_KW)
+                self.state = 42
+                self.match(MetaPromptParser.IS_KW)
                 pass
 
             elif la_ == 11:
                 self.enterOuterAlt(localctx, 11)
-                self.state = 55
-                self.match(MetaPromptParser.DEFAULT_KW)
+                self.state = 43
+                self.match(MetaPromptParser.CALL)
                 pass
 
             elif la_ == 12:
                 self.enterOuterAlt(localctx, 12)
-                self.state = 56
-                self.match(MetaPromptParser.IS_KW)
-                pass
-
-            elif la_ == 13:
-                self.enterOuterAlt(localctx, 13)
-                self.state = 57
-                self.match(MetaPromptParser.CALL)
-                pass
-
-            elif la_ == 14:
-                self.enterOuterAlt(localctx, 14)
-                self.state = 58
+                self.state = 44
                 self.match(MetaPromptParser.WITH_KW)
                 pass
 
@@ -486,71 +398,6 @@ def expr(self):
         return localctx
 
 
-    class Expr1Context(ParserRuleContext):
-        __slots__ = 'parser'
-
-        def __init__(self, parser, parent:ParserRuleContext=None, invokingState:int=-1):
-            super().__init__(parent, invokingState)
-            self.parser = parser
-
-        def meta_body(self):
-            return self.getTypedRuleContext(MetaPromptParser.Meta_bodyContext,0)
-
-
-        def exprs(self):
-            return self.getTypedRuleContext(MetaPromptParser.ExprsContext,0)
-
-
-        def getRuleIndex(self):
-            return MetaPromptParser.RULE_expr1
-
-        def enterRule(self, listener:ParseTreeListener):
-            if hasattr( listener, "enterExpr1" ):
-                listener.enterExpr1(self)
-
-        def exitRule(self, listener:ParseTreeListener):
-            if hasattr( listener, "exitExpr1" ):
-                listener.exitExpr1(self)
-
-        def accept(self, visitor:ParseTreeVisitor):
-            if hasattr( visitor, "visitExpr1" ):
-                return visitor.visitExpr1(self)
-            else:
-                return visitor.visitChildren(self)
-
-
-
-
-    def expr1(self):
-
-        localctx = MetaPromptParser.Expr1Context(self, self._ctx, self.state)
-        self.enterRule(localctx, 8, self.RULE_expr1)
-        try:
-            self.state = 63
-            self._errHandler.sync(self)
-            la_ = self._interp.adaptivePredict(self._input,3,self._ctx)
-            if la_ == 1:
-                self.enterOuterAlt(localctx, 1)
-                self.state = 61
-                self.meta_body()
-                pass
-
-            elif la_ == 2:
-                self.enterOuterAlt(localctx, 2)
-                self.state = 62
-                self.exprs()
-                pass
-
-
-        except RecognitionException as re:
-            localctx.exception = re
-            self._errHandler.reportError(self, re)
-            self._errHandler.recover(self, re)
-        finally:
-            self.exitRule()
-        return localctx
-
-
     class Meta_bodyContext(ParserRuleContext):
         __slots__ = 'parser'
 
@@ -574,6 +421,9 @@ def THEN_KW(self):
         def ELSE_KW(self):
             return self.getToken(MetaPromptParser.ELSE_KW, 0)
 
+        def RB(self):
+            return self.getToken(MetaPromptParser.RB, 0)
+
         def CHOOSE_KW(self):
             return self.getToken(MetaPromptParser.CHOOSE_KW, 0)
 
@@ -601,6 +451,9 @@ def META_PROMPT(self):
         def COMMENT_KW(self):
             return self.getToken(MetaPromptParser.COMMENT_KW, 0)
 
+        def LB(self):
+            return self.getToken(MetaPromptParser.LB, 0)
+
         def var_assignment(self):
             return self.getTypedRuleContext(MetaPromptParser.Var_assignmentContext,0)
 
@@ -649,142 +502,166 @@ def accept(self, visitor:ParseTreeVisitor):
     def meta_body(self):
 
         localctx = MetaPromptParser.Meta_bodyContext(self, self._ctx, self.state)
-        self.enterRule(localctx, 10, self.RULE_meta_body)
+        self.enterRule(localctx, 6, self.RULE_meta_body)
         self._la = 0 # Token type
         try:
             self.state = 111
             self._errHandler.sync(self)
-            la_ = self._interp.adaptivePredict(self._input,8,self._ctx)
+            la_ = self._interp.adaptivePredict(self._input,6,self._ctx)
             if la_ == 1:
                 self.enterOuterAlt(localctx, 1)
-                self.state = 65
+                self.state = 47
                 self.match(MetaPromptParser.IF_KW)
-                self.state = 66
+                self.state = 48
                 self.exprs()
-                self.state = 67
+                self.state = 49
                 self.match(MetaPromptParser.THEN_KW)
-                self.state = 68
+                self.state = 50
                 self.exprs()
-                self.state = 69
+                self.state = 51
                 self.match(MetaPromptParser.ELSE_KW)
-                self.state = 70
+                self.state = 52
                 self.exprs()
+                self.state = 53
+                self.match(MetaPromptParser.RB)
                 pass
 
             elif la_ == 2:
                 self.enterOuterAlt(localctx, 2)
-                self.state = 72
+                self.state = 55
                 self.match(MetaPromptParser.IF_KW)
-                self.state = 73
+                self.state = 56
                 self.exprs()
-                self.state = 74
+                self.state = 57
                 self.match(MetaPromptParser.THEN_KW)
-                self.state = 75
+                self.state = 58
                 self.exprs()
+                self.state = 59
+                self.match(MetaPromptParser.RB)
                 pass
 
             elif la_ == 3:
                 self.enterOuterAlt(localctx, 3)
-                self.state = 77
+                self.state = 61
                 self.match(MetaPromptParser.CHOOSE_KW)
-                self.state = 78
+                self.state = 62
                 self.exprs()
-                self.state = 80 
+                self.state = 64 
                 self._errHandler.sync(self)
                 _la = self._input.LA(1)
                 while True:
-                    self.state = 79
+                    self.state = 63
                     self.option()
-                    self.state = 82 
+                    self.state = 66 
                     self._errHandler.sync(self)
                     _la = self._input.LA(1)
                     if not (_la==12):
                         break
 
-                self.state = 85
+                self.state = 69
                 self._errHandler.sync(self)
                 _la = self._input.LA(1)
                 if _la==14:
-                    self.state = 84
+                    self.state = 68
                     self.default_option()
 
 
+                self.state = 71
+                self.match(MetaPromptParser.RB)
                 pass
 
             elif la_ == 4:
                 self.enterOuterAlt(localctx, 4)
-                self.state = 87
+                self.state = 73
                 self.match(MetaPromptParser.USE)
-                self.state = 88
+                self.state = 74
                 self.named_parameters()
+                self.state = 75
+                self.match(MetaPromptParser.RB)
                 pass
 
             elif la_ == 5:
                 self.enterOuterAlt(localctx, 5)
-                self.state = 89
+                self.state = 77
                 self.match(MetaPromptParser.META_PROMPT)
-                self.state = 90
+                self.state = 78
                 self.exprs()
+                self.state = 79
+                self.match(MetaPromptParser.RB)
                 pass
 
             elif la_ == 6:
                 self.enterOuterAlt(localctx, 6)
-                self.state = 91
+                self.state = 81
                 self.match(MetaPromptParser.COMMENT_KW)
-                self.state = 92
+                self.state = 82
                 self.exprs()
+                self.state = 83
+                self.match(MetaPromptParser.RB)
                 pass
 
             elif la_ == 7:
                 self.enterOuterAlt(localctx, 7)
-                self.state = 93
+                self.state = 85
+                self.match(MetaPromptParser.LB)
+                self.state = 86
                 self.var_assignment()
+                self.state = 87
+                self.match(MetaPromptParser.RB)
                 pass
 
             elif la_ == 8:
                 self.enterOuterAlt(localctx, 8)
-                self.state = 94
+                self.state = 89
                 self.var_optional_assignment()
                 pass
 
             elif la_ == 9:
                 self.enterOuterAlt(localctx, 9)
-                self.state = 95
+                self.state = 90
+                self.match(MetaPromptParser.LB)
+                self.state = 91
                 self.match(MetaPromptParser.VAR_NAME)
+                self.state = 92
+                self.match(MetaPromptParser.RB)
                 pass
 
             elif la_ == 10:
                 self.enterOuterAlt(localctx, 10)
-                self.state = 96
+                self.state = 93
                 self.match(MetaPromptParser.CALL)
-                self.state = 97
+                self.state = 94
                 self.call_arg1()
-                self.state = 101
+                self.state = 98
                 self._errHandler.sync(self)
                 _la = self._input.LA(1)
                 while _la==13 or _la==18:
-                    self.state = 98
+                    self.state = 95
                     self.call_arg()
-                    self.state = 103
+                    self.state = 100
                     self._errHandler.sync(self)
                     _la = self._input.LA(1)
 
+                self.state = 101
+                self.match(MetaPromptParser.RB)
                 pass
 
             elif la_ == 11:
                 self.enterOuterAlt(localctx, 11)
-                self.state = 104
+                self.state = 103
                 self.match(MetaPromptParser.CALL)
-                self.state = 108
+                self.state = 107
                 self._errHandler.sync(self)
                 _la = self._input.LA(1)
                 while _la==13 or _la==18:
-                    self.state = 105
+                    self.state = 104
                     self.call_arg()
-                    self.state = 110
+                    self.state = 109
                     self._errHandler.sync(self)
                     _la = self._input.LA(1)
 
+                self.state = 110
+                self.match(MetaPromptParser.RB)
                 pass
 
 
@@ -837,7 +714,7 @@ def accept(self, visitor:ParseTreeVisitor):
     def var_assignment(self):
 
         localctx = MetaPromptParser.Var_assignmentContext(self, self._ctx, self.state)
-        self.enterRule(localctx, 12, self.RULE_var_assignment)
+        self.enterRule(localctx, 8, self.RULE_var_assignment)
         try:
             self.enterOuterAlt(localctx, 1)
             self.state = 113
@@ -862,6 +739,9 @@ def __init__(self, parser, parent:ParserRuleContext=None, invokingState:int=-1):
             super().__init__(parent, invokingState)
             self.parser = parser
 
+        def LB(self):
+            return self.getToken(MetaPromptParser.LB, 0)
+
         def VAR_NAME(self):
             return self.getToken(MetaPromptParser.VAR_NAME, 0)
 
@@ -872,6 +752,9 @@ def exprs(self):
             return self.getTypedRuleContext(MetaPromptParser.ExprsContext,0)
 
 
+        def RB(self):
+            return self.getToken(MetaPromptParser.RB, 0)
+
         def getRuleIndex(self):
             return MetaPromptParser.RULE_var_optional_assignment
 
@@ -895,15 +778,19 @@ def accept(self, visitor:ParseTreeVisitor):
     def var_optional_assignment(self):
 
         localctx = MetaPromptParser.Var_optional_assignmentContext(self, self._ctx, self.state)
-        self.enterRule(localctx, 14, self.RULE_var_optional_assignment)
+        self.enterRule(localctx, 10, self.RULE_var_optional_assignment)
         try:
             self.enterOuterAlt(localctx, 1)
             self.state = 117
-            self.match(MetaPromptParser.VAR_NAME)
+            self.match(MetaPromptParser.LB)
             self.state = 118
-            self.match(MetaPromptParser.EQ_OPTIONAL_KW)
+            self.match(MetaPromptParser.VAR_NAME)
             self.state = 119
+            self.match(MetaPromptParser.EQ_OPTIONAL_KW)
+            self.state = 120
             self.exprs()
+            self.state = 121
+            self.match(MetaPromptParser.RB)
         except RecognitionException as re:
             localctx.exception = re
             self._errHandler.reportError(self, re)
@@ -951,20 +838,20 @@ def accept(self, visitor:ParseTreeVisitor):
     def call_arg1(self):
 
         localctx = MetaPromptParser.Call_arg1Context(self, self._ctx, self.state)
-        self.enterRule(localctx, 16, self.RULE_call_arg1)
+        self.enterRule(localctx, 12, self.RULE_call_arg1)
         try:
-            self.state = 123
+            self.state = 125
             self._errHandler.sync(self)
-            la_ = self._interp.adaptivePredict(self._input,9,self._ctx)
+            la_ = self._interp.adaptivePredict(self._input,7,self._ctx)
             if la_ == 1:
                 self.enterOuterAlt(localctx, 1)
-                self.state = 121
+                self.state = 123
                 self.var_assignment()
                 pass
 
             elif la_ == 2:
                 self.enterOuterAlt(localctx, 2)
-                self.state = 122
+                self.state = 124
                 self.exprs()
                 pass
 
@@ -1019,21 +906,21 @@ def accept(self, visitor:ParseTreeVisitor):
     def call_arg(self):
 
         localctx = MetaPromptParser.Call_argContext(self, self._ctx, self.state)
-        self.enterRule(localctx, 18, self.RULE_call_arg)
+        self.enterRule(localctx, 14, self.RULE_call_arg)
         try:
-            self.state = 128
+            self.state = 130
             self._errHandler.sync(self)
             token = self._input.LA(1)
             if token in [18]:
                 self.enterOuterAlt(localctx, 1)
-                self.state = 125
+                self.state = 127
                 self.var_assignment()
                 pass
             elif token in [13]:
                 self.enterOuterAlt(localctx, 2)
-                self.state = 126
+                self.state = 128
                 self.match(MetaPromptParser.WITH_KW)
-                self.state = 127
+                self.state = 129
                 self.exprs()
                 pass
             else:
@@ -1091,16 +978,16 @@ def accept(self, visitor:ParseTreeVisitor):
     def option(self):
 
         localctx = MetaPromptParser.OptionContext(self, self._ctx, self.state)
-        self.enterRule(localctx, 20, self.RULE_option)
+        self.enterRule(localctx, 16, self.RULE_option)
         try:
             self.enterOuterAlt(localctx, 1)
-            self.state = 130
+            self.state = 132
             self.match(MetaPromptParser.OPTION_KW)
-            self.state = 131
+            self.state = 133
             self.exprs()
-            self.state = 132
+            self.state = 134
             self.match(MetaPromptParser.IS_KW)
-            self.state = 133
+            self.state = 135
             self.exprs()
         except RecognitionException as re:
             localctx.exception = re
@@ -1148,12 +1035,12 @@ def accept(self, visitor:ParseTreeVisitor):
     def default_option(self):
 
         localctx = MetaPromptParser.Default_optionContext(self, self._ctx, self.state)
-        self.enterRule(localctx, 22, self.RULE_default_option)
+        self.enterRule(localctx, 18, self.RULE_default_option)
         try:
             self.enterOuterAlt(localctx, 1)
-            self.state = 135
+            self.state = 137
             self.match(MetaPromptParser.DEFAULT_KW)
-            self.state = 136
+            self.state = 138
             self.exprs()
         except RecognitionException as re:
             localctx.exception = re
@@ -1201,17 +1088,17 @@ def accept(self, visitor:ParseTreeVisitor):
     def named_parameters(self):
 
         localctx = MetaPromptParser.Named_parametersContext(self, self._ctx, self.state)
-        self.enterRule(localctx, 24, self.RULE_named_parameters)
+        self.enterRule(localctx, 20, self.RULE_named_parameters)
         self._la = 0 # Token type
         try:
             self.enterOuterAlt(localctx, 1)
-            self.state = 141
+            self.state = 143
             self._errHandler.sync(self)
             _la = self._input.LA(1)
             while _la==18:
-                self.state = 138
+                self.state = 140
                 self.var_assignment()
-                self.state = 143
+                self.state = 145
                 self._errHandler.sync(self)
                 _la = self._input.LA(1)
 
@@ -1260,22 +1147,22 @@ def accept(self, visitor:ParseTreeVisitor):
     def text(self):
 
         localctx = MetaPromptParser.TextContext(self, self._ctx, self.state)
-        self.enterRule(localctx, 26, self.RULE_text)
+        self.enterRule(localctx, 22, self.RULE_text)
         try:
             self.enterOuterAlt(localctx, 1)
-            self.state = 145 
+            self.state = 147 
             self._errHandler.sync(self)
             _alt = 1
             while _alt!=2 and _alt!=ATN.INVALID_ALT_NUMBER:
                 if _alt == 1:
-                    self.state = 144
+                    self.state = 146
                     self.match(MetaPromptParser.CHAR)
 
                 else:
                     raise NoViableAltException(self)
-                self.state = 147 
+                self.state = 149 
                 self._errHandler.sync(self)
-                _alt = self._interp.adaptivePredict(self._input,12,self._ctx)
+                _alt = self._interp.adaptivePredict(self._input,10,self._ctx)
 
         except RecognitionException as re:
             localctx.exception = re
diff --git a/python/src/parser/MetaPromptVisitor.py b/python/src/parser/MetaPromptVisitor.py
index e872947..e7c71ff 100644
--- a/python/src/parser/MetaPromptVisitor.py
+++ b/python/src/parser/MetaPromptVisitor.py
@@ -19,21 +19,11 @@ def visitExprs(self, ctx:MetaPromptParser.ExprsContext):
         return self.visitChildren(ctx)
 
 
-    # Visit a parse tree produced by MetaPromptParser#exprs1.
-    def visitExprs1(self, ctx:MetaPromptParser.Exprs1Context):
-        return self.visitChildren(ctx)
-
-
     # Visit a parse tree produced by MetaPromptParser#expr.
     def visitExpr(self, ctx:MetaPromptParser.ExprContext):
         return self.visitChildren(ctx)
 
 
-    # Visit a parse tree produced by MetaPromptParser#expr1.
-    def visitExpr1(self, ctx:MetaPromptParser.Expr1Context):
-        return self.visitChildren(ctx)
-
-
     # Visit a parse tree produced by MetaPromptParser#meta_body.
     def visitMeta_body(self, ctx:MetaPromptParser.Meta_bodyContext):
         return self.visitChildren(ctx)
diff --git a/python/tests/test_parser.py b/python/tests/test_parser.py
index 4300e0f..d62ee85 100644
--- a/python/tests/test_parser.py
+++ b/python/tests/test_parser.py
@@ -112,7 +112,7 @@ def test_escaping_1():
 
 
 def test_escaping_2():
-    result = parse("\\[:foo]")
+    result = parse("\\[:foo\\]")
     assert result == [t("[:foo]")]
 
 
@@ -132,8 +132,9 @@ def test_escaping_3():
 
 
 def test_escaping_4():
-    result = parse("\\\\[")
-    assert result == [t("\\\\[")]
+    bs="\\"
+    result = parse(f"{bs}{bs}{bs}[")
+    assert result == [t(f"{bs}[")]
 
 
 def test_escaping_5():
@@ -206,27 +207,27 @@ def test_if_nested():
 
 
 def test_dummy_meta():
-    result = parse("[test]")
+    result = parse("\[test\]")
     assert result == [t("[test]")]
 
 
 def test_dummy_meta2():
-    result = parse("[[]]")
+    result = parse("\\[\\[\\]\\]")
     assert result == [t("[[]]")]
 
 
 def test_dummy_meta3():
-    result = parse("[a")
-    assert result == [t("[a")]
+    result = parse("\\[a")
+    assert result == [t("\\[a")]
 
 
 def test_dummy_meta4():
-    result = parse("[[][]]")
+    result = parse("\\[\\[\\]\\[\\]\\]")
     assert result == [t("[[][]]")]
 
 
 def test_meta2():
-    result = parse("[$ []]")
+    result = parse("[$ \\[\\]]")
     assert result == [meta([t(" []")])]
 
 
@@ -331,7 +332,7 @@ def test_use_nested():
 
 
 def test_use_nested_2():
-    result = parse("[:use foo :asd=[hiiii [:use bar :qux=asd]] hiii :foo=bar]")
+    result = parse("[:use foo :asd=\\[hiiii [:use bar :qux=asd]\\] hiii :foo=bar]")
     assert result == [
         {
             "type": "use",