instance_cache1.lean:4:2: error: failed to synthesize type class instance for
A : Type ?,
a : A,
this : has_add A
⊢ has_add A
instance_cache1.lean:7:7: error: failed to synthesize type class instance for
A : Type ?,
a : A,
s : has_add A
⊢ has_add A
instance_cache1.lean:10:19: error: failed to synthesize type class instance for
A : Type ?,
a : A,
s : has_add A
⊢ has_add A