Nuprl Lemma : sp-join-com

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


Proof




Definitions occuring in Statement :  sp-join: f ∨ g,  Sierpinski: Sierpinski,  uall: ∀[x:A]. B[x],  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  uiff: uiff(P;Q),  and: P ∧ Q,  uimplies: b supposing a,  iff: P ⇐⇒ Q,  implies: P ⇒ Q,  rev_implies: P ⇐ Q,  cand: A c∧ B,  prop: ℙ,  subtype_rel: A ⊆r 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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