Nuprl Lemma : find_wf

[T:Type]. ∀[P:T ⟶ 𝔹]. ∀[as:T List]. ∀[d:T].  ((first a ∈ as s.t. P[a] else d) ∈ T)


Proof




Definitions occuring in Statement :  find: (first x ∈ as s.t. P[x] else d) list: List bool: 𝔹 uall: [x:A]. B[x] so_apply: x[s] member: t ∈ T function: x:A ⟶ B[x] universe: Type
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T find: (first x ∈ as s.t. P[x] else d) so_lambda: so_lambda(x,y,z.t[x; y; z]) so_apply: x[s1;s2;s3] so_apply: x[s] prop:
Lemmas referenced :  list_ind_wf list_wf filter_wf5 l_member_wf bool_wf
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation_alt introduction cut sqequalRule extract_by_obid sqequalHypSubstitution isectElimination thin hypothesisEquality lambdaEquality hypothesis applyEquality setElimination rename setEquality axiomEquality equalityTransitivity equalitySymmetry universeIsType isect_memberEquality because_Cache functionIsType functionEquality universeEquality

Latex:
\mforall{}[T:Type].  \mforall{}[P:T  {}\mrightarrow{}  \mBbbB{}].  \mforall{}[as:T  List].  \mforall{}[d:T].    ((first  a  \mmember{}  as  s.t.  P[a]  else  d)  \mmember{}  T)



Date html generated: 2019_10_15-AM-10_53_55
Last ObjectModification: 2018_09_27-AM-09_38_59

Theory : list!


Home Index