As powerful as an interpreter might be for running programs, it isn't the right tool for designing programs. Validating a program design requires static analysi

As powerful as an interpreter might be for running programs, it isn't the right tool for designing programs. Validating a program design requires static analysis, to be performed either mechanically (e.g., type checking) or manually (e.g., manipulating predicate transformers in the way advocated by Dijkstra).