VDM-SL, 64 bytes
f(a)==forall y in set inds a&card{x|x in set inds a&a(x)=a(y)}=2
Expired Data
- 4k
- 1
- 11
- 34
f(a)==forall y in set inds a&card{x|x in set inds a&a(x)=a(y)}=2