[Agda] parameters vs indices

[Thorsten Altenkirch]

Hi,

this came up during Conor's Agda course at the Types summer school.

It is a bit surprising that the following is accepted

data Good : Set → Set where
  good : (X : Set) → Good X

This looks like we have a large constructor. However, if we want to cheat Agda complains

data Bad : Set → Set where
  bad : {X : Set} → Bad ℕ

Indeed Good is equivalent to Honest which uses a parameter

data Honest (X : Set) : Set where
  honest : Honest X

Why don't we force people to be Honest instead of just being Good?
Thorsten




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