by_cases spacing

Stream: mathlib4

[Kevin Buzzard]

I've just noticed that mathlib3port is changing by_cases h : x = y to by_cases h:x = y (removing spaces). Is this intentional? I'm just finishing up the port of logic.relation and comparing my file with the autoported file I noticed this.

[Mario Carneiro]

No, it's usually the fault of some missing spaces in the syntax definitions