Nuprl Lemma : exists-product1

[A,B:Type].  ∀P:(A × B) ⟶ ℙ'. {∃x:A × B. P[x] ⇐⇒ ∃a:A. ∃b:B. P[<a, b>]}


Proof




Definitions occuring in Statement :  uall: [x:A]. B[x] prop: guard: {T} so_apply: x[s] all: x:A. B[x] exists: x:A. B[x] iff: ⇐⇒ Q function: x:A ⟶ B[x] pair: <a, b> product: x:A × B[x] universe: Type
Definitions unfolded in proof :  guard: {T} uall: [x:A]. B[x] all: x:A. B[x] iff: ⇐⇒ Q and: P ∧ Q implies:  Q exists: x:A. B[x] member: t ∈ T prop: so_apply: x[s] so_lambda: λ2x.t[x] rev_implies:  Q
Lemmas referenced :  exists_wf
Rules used in proof :  sqequalSubstitution sqequalRule sqequalReflexivity sqequalTransitivity computationStep isect_memberFormation lambdaFormation independent_pairFormation sqequalHypSubstitution productElimination thin dependent_pairFormation hypothesisEquality hypothesis applyEquality independent_pairEquality cut instantiate lemma_by_obid isectElimination cumulativity lambdaEquality productEquality functionEquality universeEquality

Latex:
\mforall{}[A,B:Type].    \mforall{}P:(A  \mtimes{}  B)  {}\mrightarrow{}  \mBbbP{}'.  \{\mexists{}x:A  \mtimes{}  B.  P[x]  \mLeftarrow{}{}\mRightarrow{}  \mexists{}a:A.  \mexists{}b:B.  P[<a,  b>]\}



Date html generated: 2016_05_15-PM-03_22_54
Last ObjectModification: 2015_12_27-PM-01_05_37

Theory : general


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