AGDA_FAILURE

ret > ExitFailure 42
out > Issue2636.agda:8,1-18,37
out > D is not strictly positive, because it occurs
out > to the left of an arrow
out > in the first argument of F
out > (in the first argument of id
out >  in the first clause
out >  in the definition of lemma), which occurs
out >                             in the first clause
out >                             in the definition of F, which occurs
out >                                                   in the type of the constructor c
out >                                                   in the definition of D.
out >
