Nuprl Lemma : exists-unit

∀P:Unit ⟶ ℙ. (∃x:Unit. P[x] ⇐⇒ P[⋅])


Proof




Definitions occuring in Statement :  it: ⋅,  prop: ℙ,  so_apply: x[s],  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  iff: P ⇐⇒ Q,  unit: Unit,  function: x:A ⟶ B[x]
Definitions unfolded in proof :  all: ∀x:A. B[x],  iff: P ⇐⇒ Q,  and: P ∧ Q,  implies: P ⇒ Q,  exists: ∃x:A. B[x],  unit: Unit,  member: t ∈ T,  it: ⋅,  prop: ℙ,  uall: ∀[x:A]. B[x],  so_lambda: λ2x.t[x],  so_apply: x[s],  rev_implies: P ⇐ Q
Lemmas referenced :  exists_wf,  unit_wf2,  it_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  independent_pairFormation,  sqequalHypSubstitution,  productElimination,  thin,  equalityElimination,  hypothesis,  cut,  lemma_by_obid,  isectElimination,  sqequalRule,  lambdaEquality,  applyEquality,  hypothesisEquality,  dependent_pairFormation,  functionEquality,  cumulativity,  universeEquality

Latex:
\mforall{}P:Unit  {}\mrightarrow{}  \mBbbP{}.  (\mexists{}x:Unit.  P[x]  \mLeftarrow{}{}\mRightarrow{}  P[\mcdot{}])



Date html generated: 2016_05_15-PM-03_24_53
Last ObjectModification: 2015_12_27-PM-01_06_18

Theory : general


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