example.lc

# This is using the standard library function POW, ints are Church Numerals, bools are Church Booleans
int :: POW 2 3;

# This is the same result but printed as a function
function :: POW 2 3;

# Same as above
POW 2 3;

# If you try to print as a datatype when it is not, it will revert to a function
bool :: POW 2 3;

# This is an example of an actual bool
bool :: IS_EVEN 6;
IS_EVEN 6;

# 0 happens to be defined as equal to FALSE
0;
FALSE;
int :: IS_EVEN 7;

# However TRUE is not a valid int
1;
TRUE;
int :: IS_EVEN 6;

# You can define your own functions as well
MY_FUNC := (\b.\e.e b);

# MY_FUNC happens to be the same as the stdlib function POW
int :: MY_FUNC 2 3;

# You can use a combination of backslash and λ
(\hi_im_a_var.λim_also_a_var.TRUE 1 0);

# We can get fancy with recursion using the Y-Combinator stdlib function
MY_REC := Y (\r.\m.
    IF_THEN_ELSE (IS_ZERO m) 
        1 
        ( MULT m (r (PRED m)) )
);

# This prints factorial(4)
int :: MY_REC 4;

# You can take it from there (whitespace is ignored!)