Nuprl Lemma : not-l_all-dec

[T:Type]. ∀L:T List. ∀P:T ⟶ ℙ.  ((∀x:T. Dec(P[x]))  (∀x∈L.P[x]) ⇐⇒ (∃x∈L. ¬P[x])))


Proof




Definitions occuring in Statement :  l_exists: (∃x∈L. P[x]) l_all: (∀x∈L.P[x]) list: List decidable: Dec(P) uall: [x:A]. B[x] prop: so_apply: x[s] all: x:A. B[x] iff: ⇐⇒ Q not: ¬A implies:  Q function: x:A ⟶ B[x] universe: Type
Definitions unfolded in proof :  uall: [x:A]. B[x] all: x:A. B[x] implies:  Q iff: ⇐⇒ Q and: P ∧ Q member: t ∈ T prop: so_lambda: λ2x.t[x] so_apply: x[s] rev_implies:  Q not: ¬A false: False decidable: Dec(P) or: P ∨ Q exists: x:A. B[x]
Lemmas referenced :  not_wf l_all_wf l_member_wf l_exists_wf all_wf decidable_wf list_wf not-l_exists l_all_iff decidable__l_exists decidable__not l_exists_iff
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation lambdaFormation independent_pairFormation cut lemma_by_obid sqequalHypSubstitution isectElimination thin hypothesisEquality sqequalRule lambdaEquality applyEquality setElimination rename setEquality hypothesis independent_functionElimination voidElimination functionEquality cumulativity universeEquality because_Cache dependent_functionElimination productElimination unionElimination

Latex:
\mforall{}[T:Type].  \mforall{}L:T  List.  \mforall{}P:T  {}\mrightarrow{}  \mBbbP{}.    ((\mforall{}x:T.  Dec(P[x]))  {}\mRightarrow{}  (\mneg{}(\mforall{}x\mmember{}L.P[x])  \mLeftarrow{}{}\mRightarrow{}  (\mexists{}x\mmember{}L.  \mneg{}P[x])))



Date html generated: 2016_05_14-AM-07_48_07
Last ObjectModification: 2015_12_26-PM-02_55_35

Theory : list_1


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