Type checker's expected and inferred types (reformatted)

[Albert Y. C. Lai]

For the record, and to speak up as part of a possible silent majority,

I completely understand the type error messages. I find enough 
information in them. I like them.

I find it unnecessary to "decrypt" the two words "expected" and 
"inferred". They have their own definitions and they stand for 
themselves; "external" and "internal" are helpful mnemonics, useful 
approximation, but not decryption.

I support work on ghc to prioritize professional use over pedagogical 
use, that is, if a proposed pedagogical improvement conflicts with 
professional use concerns, or even if simply no one has time to 
implement, I support sacrificing the pedagogical improvement. To 
mitigate the sacrifice, we users write tutorials for each other.