Based on the article, I reckon it takes the arg:type syntax from Delphi. Pascal, to the best of my knowledge, was the first language to use such notation. I thi

Based on the article, I reckon it takes the arg:type syntax from Delphi. Pascal, to the best of my knowledge, was the first language to use such notation. I think it's likely that ML borrowed that syntax from Pascal, but I can't prove it.