Nuprl Lemma : can-apply-p-first

[A,B:Type].  ∀L:(A ⟶ (B Top)) List. ∀x:A.  (↑can-apply(p-first(L);x) ⇐⇒ (∃f∈L. ↑can-apply(f;x)))


Proof




Definitions occuring in Statement :  p-first: p-first(L) can-apply: can-apply(f;x) l_exists: (∃x∈L. P[x]) list: List assert: b uall: [x:A]. B[x] top: Top all: x:A. B[x] iff: ⇐⇒ Q function: x:A ⟶ B[x] union: left right universe: Type
Definitions unfolded in proof :  uall: [x:A]. B[x] all: x:A. B[x] member: t ∈ T so_lambda: λ2x.t[x] subtype_rel: A ⊆B uimplies: supposing a so_apply: x[s] top: Top prop: implies:  Q assert: b ifthenelse: if then else fi  bfalse: ff iff: ⇐⇒ Q and: P ∧ Q false: False rev_implies:  Q append: as bs so_lambda: so_lambda(x,y,z.t[x; y; z]) so_apply: x[s1;s2;s3] or: P ∨ Q squash: T true: True guard: {T} uiff: uiff(P;Q)
Lemmas referenced :  p-first-singleton p-first-append true_wf squash_wf append_wf l_exists_append l_exists_cons p-conditional-to-p-first assert_functionality_wrt_uiff or_wf p-conditional_wf nil_wf cons_wf p-conditional-domain list_ind_nil_lemma list_ind_cons_lemma l_exists_wf_nil l_exists_nil false_wf p_first_nil_lemma list_wf l_member_wf l_exists_wf subtype_rel_union subtype_rel_dep_function subtype_rel_list p-first_wf can-apply_wf assert_wf iff_wf all_wf top_wf list_induction
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation lambdaFormation cut thin lemma_by_obid sqequalHypSubstitution isectElimination functionEquality hypothesisEquality unionEquality hypothesis sqequalRule lambdaEquality cumulativity because_Cache applyEquality independent_isectElimination isect_memberEquality voidElimination voidEquality setElimination rename setEquality independent_functionElimination dependent_functionElimination universeEquality introduction independent_pairFormation productElimination independent_pairEquality addLevel allFunctionality impliesFunctionality imageElimination equalitySymmetry natural_numberEquality imageMemberEquality baseClosed orFunctionality equalityTransitivity unionElimination inlFormation inrFormation

Latex:
\mforall{}[A,B:Type].
    \mforall{}L:(A  {}\mrightarrow{}  (B  +  Top))  List.  \mforall{}x:A.    (\muparrow{}can-apply(p-first(L);x)  \mLeftarrow{}{}\mRightarrow{}  (\mexists{}f\mmember{}L.  \muparrow{}can-apply(f;x)))



Date html generated: 2016_05_15-PM-03_45_17
Last ObjectModification: 2016_01_16-AM-10_56_40

Theory : general


Home Index