What do LT and GT mean?

Question

GHCi> compare 2 3
LT
GHCi> compare 3 3
EQ
GHCi> compare 4 3
GT

I think EQ means equal, but what do LT and GT mean?

Answer 1

• compare 2 3 = LT — 2 is Less Than 3
• compare 3 3 = EQ — 3 is EQual to 3
• compare 4 3 = GT — 4 is Greater Than 3

It's unfortunate that the documentation for Ordering does not explicitly spell this out.

Answer 2

It's not in haskell only, GT and LT are very common and well known acronyms respectively for Greater Than and Less Than. Other common acronyms for comparisons include GE and LE, i.e. Greater or Equal and Less or Equal, but they are not part of the Haskell's Ordering data constructors. You are right about EQ = "equal".