[ "fail - 0 is not truthy" println! ] [ "OK" println! ] 0 if!
[ "OK" println! ] [ "fail - 1 is truthy" println! ] 1 if!
[ "OK" println! ] [ "fail - 1.1 is truthy" println! ] 1.1 if!
[ "OK" println! ] [ "fail - 0.1 is truthy" println! ] 0.1 if!
[ "OK" println! ] [ "fail - -0.1 is truthy" println! ] -0.1 if!
[ "fail - -0.0 is not truthy" println! ] [ "OK" println! ] -0.0 if!
[ "fail - 0.0 is not truthy" println! ] [ "OK" println! ] 0.0 if!