Unexpected behaviour of Any opperator

[Rafael7991]

This grammar accepts inputs that it should not.

apeg testfunction;

start: teste<0,1, resp>;

teste[int x, int y] returns z : { z = x+y; } strN<z*2> ;

strN[int n] : ( {? n > 0 } CHAR { n = n - 1; } )* {? n == 0 } !_ ;

CHAR : _ ;