LISP had the convention of appending "p" for predicate: (evenp x) would return true if x was even. So, "positivep". Though, yeah, that would be the name for a

LISP had the convention of appending "p" for predicate: (evenp x) would return true if x was even. So, "positivep". Though, yeah, that would be the name for a function that checks whether the argument was positive, not a flag.