Nuprl Lemma : ancestral-logic-lemma1

∀x,y:Dom.  (TC(λa,b.R a b)(x,y) ⇒ ((R x y) ∨ (∃z:Dom. ((R x z) ∧ TC(λa,b.R a b)(z,y)))))


Proof




Definitions occuring in Statement :  TC: TC(λx,y.F[x; y])(a,b),  language1: language1{i:l}(D,A,B,C,P,Q,R,H.fml[D;A;B;C;P;Q;R;H]),  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  implies: P ⇒ Q,  or: P ∨ Q,  and: 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,  all: ∀x:A. B[x],  implies: P ⇒ Q,  or: P ∨ Q,  so_lambda: λ2x.t[x],  so_lambda: λ2x y.t[x; y],  so_apply: x[s1;s2],  so_apply: x[s],  guard: {T},  exists: ∃x:A. B[x],  and: P ∧ Q
Lemmas referenced :  exists_wf,  and_wf,  TC_wf,  TC-min,  or_wf,  TC-base,  TC-trans
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  sqequalHypSubstitution,  functionEquality,  cumulativity,  hypothesisEquality,  universeEquality,  because_Cache,  cut,  lambdaFormation,  inlFormation,  lemma_by_obid,  isectElimination,  thin,  sqequalRule,  lambdaEquality,  applyEquality,  hypothesis,  independent_functionElimination,  inrFormation,  unionElimination,  dependent_pairFormation,  independent_pairFormation,  dependent_functionElimination,  productElimination

Latex:
\mforall{}x,y:Dom.    (TC(\mlambda{}a,b.R  a  b)(x,y)  {}\mRightarrow{}  ((R  x  y)  \mvee{}  (\mexists{}z:Dom.  ((R  x  z)  \mwedge{}  TC(\mlambda{}a,b.R  a  b)(z,y)))))



Date html generated: 2016_05_16-AM-09_08_18
Last ObjectModification: 2015_12_28-PM-07_03_33

Theory : first-order!and!ancestral!logic


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