Nuprl Lemma : bnot_thru_exists

A:Type. ∀as:A List. ∀f:A ⟶ 𝔹.  ¬b(∃bx(:A) ∈ as. f[x]) = ∀bx(:A) ∈ as. bf[x])


Proof




Definitions occuring in Statement :  bexists: bexists ball: ball list: List bnot: ¬bb bool: 𝔹 so_apply: x[s] all: x:A. B[x] function: x:A ⟶ B[x] universe: Type equal: t ∈ T
Definitions unfolded in proof :  all: x:A. B[x] uall: [x:A]. B[x] member: t ∈ T so_lambda: λ2x.t[x] so_apply: x[s] implies:  Q top: Top bnot: ¬bb ifthenelse: if then else fi  bfalse: ff squash: T prop: true: True bool: 𝔹 unit: Unit it: btrue: tt band: p ∧b q uiff: uiff(P;Q) and: P ∧ Q uimplies: supposing a exists: x:A. B[x] or: P ∨ Q sq_type: SQType(T) guard: {T} assert: b false: False subtype_rel: A ⊆B iff: ⇐⇒ Q rev_implies:  Q
Lemmas referenced :  list_induction all_wf bool_wf equal_wf bnot_wf bexists_wf ball_wf list_wf bexists_nil_lemma ball_nil_lemma btrue_wf bexists_cons_lemma ball_cons_lemma bnot_thru_bor squash_wf true_wf band_wf eqtt_to_assert bool_cases_sqequal subtype_base_sq bool_subtype_base eqff_to_assert assert-bnot iff_weakening_equal
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity lambdaFormation cut thin introduction extract_by_obid sqequalHypSubstitution isectElimination hypothesisEquality sqequalRule lambdaEquality functionEquality cumulativity hypothesis dependent_functionElimination applyEquality functionExtensionality independent_functionElimination isect_memberEquality voidElimination voidEquality rename imageElimination because_Cache equalityTransitivity equalitySymmetry natural_numberEquality imageMemberEquality baseClosed unionElimination equalityElimination productElimination independent_isectElimination dependent_pairFormation promote_hyp instantiate universeEquality

Latex:
\mforall{}A:Type.  \mforall{}as:A  List.  \mforall{}f:A  {}\mrightarrow{}  \mBbbB{}.    \mneg{}\msubb{}(\mexists{}\msubb{}x(:A)  \mmember{}  as.  f[x])  =  \mforall{}\msubb{}x(:A)  \mmember{}  as.  (\mneg{}\msubb{}f[x])



Date html generated: 2017_10_01-AM-09_56_00
Last ObjectModification: 2017_03_03-PM-00_56_08

Theory : list_2


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