Before the first ANSI standard, we had the C Reference Manual in the back of K&R1. The definition was merely less rigorous (and that lack of rigor often led to

Before the first ANSI standard, we had the C Reference Manual in the back of K&R1. The definition was merely less rigorous (and that lack of rigor often led to complex nests of "#ifdef"s). If a compiler generated code that evaluated 2 + 2 and yielded a result of 5, we could confidently say that compiler had a bug.