$_ = "it's 94% fat-free!";    # a string that should match

# the following code works but the logic is outside the RE
print "match\n" if (/(\d{1,3})%/, $1>91);

# the following code also works but is offensive
print "match\n" if /(\d{1,3})%(?(?{$1>91})(?:.*)|(?!.*))/;