This example is interesting, in that the suggestion for canonical "<" (as apposed to ">") results in awkward code: if (index < xs.len) { // Not the point

This example is interesting, in that the suggestion for canonical "<" (as apposed to ">") results in awkward code: if (index < xs.len) { // Not the point } else { // The condition we wanted to do something } Which would be fixed (still using "<") with a NOT operator. But, I have noticed that I feel slightly irritated by the extra parens that introducing NOT operators often causes: if (!(condition expression)) { // The condition we wanted to do something } Given NOT is always a unary operation, it would be some nice sugar if "if" clauses didn't require parens for "notting" the condition: if !(condition expression) { // The condition we wanted to do something } Or we could have "ifnot" clauses, to be clearer. ifnot (condition expression) { // The condition we wanted to do something } Point being, sometimes it feels easier to test for false than true, based on the variable meanings and context. (All this syntax fine tuning, is at least amusing.)