Nuprl Lemma : exists-simp-test

∀T:Type. ∀P:T ⟶ ℙ'. ∀a:T.  (∃x:T. (P[x] ∧ (x = a ∈ T)) ⇐⇒ P[a])


Proof




Definitions occuring in Statement :  prop: ℙ,  so_apply: x[s],  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  iff: P ⇐⇒ Q,  and: P ∧ Q,  function: x:A ⟶ B[x],  universe: Type,  equal: s = t ∈ T
Definitions unfolded in proof :  all: ∀x:A. B[x],  iff: P ⇐⇒ Q,  and: P ∧ Q,  implies: P ⇒ Q,  exists: ∃x:A. B[x],  prop: ℙ,  member: t ∈ T,  uall: ∀[x:A]. B[x],  so_apply: x[s],  so_lambda: λ2x.t[x],  subtype_rel: A ⊆r B,  rev_implies: P ⇐ Q
Lemmas referenced :  and_wf,  equal_wf,  exists_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  independent_pairFormation,  sqequalHypSubstitution,  productElimination,  thin,  cut,  hypothesis,  addLevel,  hyp_replacement,  equalitySymmetry,  sqequalRule,  dependent_set_memberEquality,  hypothesisEquality,  introduction,  extract_by_obid,  isectElimination,  applyLambdaEquality,  setElimination,  rename,  applyEquality,  levelHypothesis,  instantiate,  cumulativity,  lambdaEquality,  productEquality,  functionExtensionality,  universeEquality,  dependent_pairFormation,  because_Cache,  functionEquality

Latex:
\mforall{}T:Type.  \mforall{}P:T  {}\mrightarrow{}  \mBbbP{}'.  \mforall{}a:T.    (\mexists{}x:T.  (P[x]  \mwedge{}  (x  =  a))  \mLeftarrow{}{}\mRightarrow{}  P[a])



Date html generated: 2017_10_01-AM-09_10_43
Last ObjectModification: 2017_07_26-PM-04_47_02

Theory : general


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