zf3.nql

global tree;
global nexttree;
global stack;

global t0;
global t1;
global t2;

/* Cantor pair manipulation proctions */
/* zeros in1, in2 */
proc pair(out, in1, in2) {
    builtin_pair(out, in1, in2);
}

/* zeros in */
proc unpair(out1, out2, in) {
    builtin_unpair(out1, out2, in);
}

proc main() {
    nexttree = nexttree + 1;
    if (tree == 0) {
        tree = nexttree;
    }

    unpair(t0, tree, tree);
    while (tree > 0) {
        pair(stack, stack, t0);
        unpair(t0, tree, tree);
    }

    t1 = nexttree;
    while (t1 > 0) {
        t1 = t1 - 1;
        t2 = t0;
        pair(tree, tree, t0);
        builtin_add(t0, t2);
    }

    while (stack > 0) {
        unpair(stack, t0, stack);
        pair(tree, t0, tree);
    }
}