Nuprl Lemma : fo-logic-test1

∀x.(B x) ⇒ (C x) ⇒ ∃x.B x ⇒ ∃x.C x


Proof




Definitions occuring in Statement :  language1: language1{i:l}(D,A,B,C,P,Q,R,H.fml[D;A;B;C;P;Q;R;H]),  forsome: ∃x.P[x],  forall: ∀x.P[x],  implies: P ⇒ Q,  apply: f a
Definitions unfolded in proof :  language1: language1{i:l}(D,A,B,C,P,Q,R,H.fml[D;A;B;C;P;Q;R;H]),  uall: ∀[x:A]. B[x],  !hyp_hide: x,  member: t ∈ T,  prop: ℙ,  implies: P ⇒ Q,  so_lambda: λ2x.t[x],  so_apply: x[s],  forsome: ∃x.P[x],  exists: ∃x:A. B[x],  forall: ∀x.P[x],  all: ∀x:A. B[x]
Lemmas referenced :  forsome_wf,  forall_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  sqequalHypSubstitution,  functionEquality,  cumulativity,  hypothesisEquality,  universeEquality,  because_Cache,  lambdaFormation,  cut,  lemma_by_obid,  isectElimination,  thin,  sqequalRule,  lambdaEquality,  applyEquality,  hypothesis,  productElimination,  addLevel,  dependent_functionElimination,  levelHypothesis,  independent_functionElimination,  dependent_pairFormation

Latex:
\mforall{}x.(B  x)  {}\mRightarrow{}  (C  x)  {}\mRightarrow{}  \mexists{}x.B  x  {}\mRightarrow{}  \mexists{}x.C  x



Date html generated: 2016_05_16-AM-09_07_56
Last ObjectModification: 2015_12_28-PM-07_03_18

Theory : first-order!and!ancestral!logic


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