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: ℙ,  guard: {T},  so_apply: x[s],  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  iff: P ⇐⇒ 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: P ⇐⇒ Q,  and: P ∧ Q,  implies: P ⇒ Q,  exists: ∃x:A. B[x],  member: t ∈ T,  prop: ℙ,  so_apply: x[s],  so_lambda: λ2x.t[x],  rev_implies: P ⇐ 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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