f:(TopTop), n:, l:Top List. firstn(n;map(f;l)) ~ map(f;firstn(n;l)) 

latex

Definitions	Unit, P  Q, P & Q, P  Q, T, i<j, , ij, b, b, True, Prop, map(f;as), AB, A, False, ij, P  Q, Top, x:A. B(x), t  T,
Lemmas	nat wf, top wf, nat properties, ge wf, map wf, first0, bnot wf, assert wf, le wf, le int wf, bool wf, lt int wf, assert of le int, bnot of lt int, true wf, squash wf, eqff to assert, iff transitivity, assert of lt int, eqtt to assert