Nuprl Lemma : ancestral-logic-lemma1

x,y:Dom.  (TC(λa,b.R b)(x,y)  ((R y) ∨ (∃z:Dom. ((R z) ∧ TC(λa,b.R 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:  Q or: P ∨ Q and: P ∧ Q apply: 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: all: x:A. B[x] implies:  Q or: P ∨ Q so_lambda: λ2x.t[x] so_lambda: λ2y.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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