Nuprl Lemma : can-apply-p-filter

[T:Type]. ∀[P:T ⟶ ℙ].  ∀f:∀x:T. Dec(P[x]). ∀x:T.  (↑can-apply(p-filter(f);x) ⇐⇒ P[x])


Proof




Definitions occuring in Statement :  p-filter: p-filter(f) can-apply: can-apply(f;x) assert: b decidable: Dec(P) uall: [x:A]. B[x] prop: so_apply: x[s] all: x:A. B[x] iff: ⇐⇒ Q function: x:A ⟶ B[x] universe: Type
Definitions unfolded in proof :  uall: [x:A]. B[x] all: x:A. B[x] p-filter: p-filter(f) can-apply: can-apply(f;x) member: t ∈ T prop: so_lambda: λ2x.t[x] so_apply: x[s] implies:  Q decidable: Dec(P) or: P ∨ Q isl: isl(x) assert: b ifthenelse: if then else fi  btrue: tt iff: ⇐⇒ Q and: P ∧ Q rev_implies:  Q true: True bfalse: ff false: False not: ¬A
Lemmas referenced :  all_wf decidable_wf true_wf false_wf equal_wf
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation lambdaFormation sqequalRule hypothesisEquality cut lemma_by_obid sqequalHypSubstitution isectElimination thin lambdaEquality applyEquality hypothesis functionEquality cumulativity universeEquality unionElimination independent_pairFormation natural_numberEquality voidElimination independent_functionElimination equalityTransitivity equalitySymmetry dependent_functionElimination

Latex:
\mforall{}[T:Type].  \mforall{}[P:T  {}\mrightarrow{}  \mBbbP{}].    \mforall{}f:\mforall{}x:T.  Dec(P[x]).  \mforall{}x:T.    (\muparrow{}can-apply(p-filter(f);x)  \mLeftarrow{}{}\mRightarrow{}  P[x])



Date html generated: 2016_05_15-PM-03_30_55
Last ObjectModification: 2015_12_27-PM-01_10_54

Theory : general


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