Nuprl Lemma : sp-join-com

[x,y:Sierpinski].  (x ∨ y ∨ x ∈ Sierpinski)


Proof




Definitions occuring in Statement :  sp-join: f ∨ g Sierpinski: Sierpinski uall: [x:A]. B[x] equal: t ∈ T
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T uiff: uiff(P;Q) and: P ∧ Q uimplies: supposing a iff: ⇐⇒ Q implies:  Q rev_implies:  Q cand: c∧ B prop: subtype_rel: A ⊆B
Lemmas referenced :  Sierpinski-equal sp-join_wf sp-join-is-bottom equal_wf Sierpinski_wf Sierpinski-bottom_wf subtype-Sierpinski
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation introduction cut lemma_by_obid sqequalHypSubstitution isectElimination thin hypothesisEquality hypothesis productElimination independent_isectElimination independent_pairFormation lambdaFormation independent_functionElimination applyEquality sqequalRule because_Cache isect_memberEquality axiomEquality

Latex:
\mforall{}[x,y:Sierpinski].    (x  \mvee{}  y  =  y  \mvee{}  x)



Date html generated: 2019_10_31-AM-06_36_33
Last ObjectModification: 2015_12_28-AM-11_21_00

Theory : synthetic!topology


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