Yellow highlight in Agda

Question

I write the below code in Agda.

open import Relation.Binary.PropositionalEquality
open import Data.Unit

data  : Set where
    tt : 
    ff : 

test_a : tt ≡ tt
test_a = refl

test_b : ff ≡ ff
test_b = refl

When I load the above code, I get yellow highlight with

tt ≡ tt

at line 8. What is wrong with the code?

I'm sorry not to include all the imports. To use3237465, thank you for pointing out. To Cactus, thank you for adding all the imports. — mmsss, Apr 26 '16 at 07:53

score 1 · Accepted Answer · answered Apr 26 '16 at 04:55

Perhaps you imported Data.Unit or Data.Unit.Base which introduced another tt (namely the inhabitant of ⊤), so Agda is confused about which one to choose. You can write

test_a : .tt ≡ tt
test_a = refl

or

import Function

test_a : ( ∋ tt) ≡ tt
test_a = refl

Yellow highlight in Agda

1 Answers1