Nuprl Lemma : or-quotient-true-subtype

∀P:ℙ. (⇃(P ∨ (¬P)) ⊆r (⇃(P) ∨ ⇃(¬P)))


Proof




Definitions occuring in Statement :  quotient: x,y:A//B[x; y],  subtype_rel: A ⊆r B,  prop: ℙ,  all: ∀x:A. B[x],  not: ¬A,  or: P ∨ Q,  true: True
Definitions unfolded in proof :  all: ∀x:A. B[x],  or: P ∨ Q,  uall: ∀[x:A]. B[x],  member: t ∈ T,  prop: ℙ,  uimplies: b supposing a,  not: ¬A,  implies: P ⇒ Q,  and: P ∧ Q,  false: False,  so_lambda: λ2x y.t[x; y],  so_apply: x[s1;s2]
Lemmas referenced :  disjoint-quotient_subtype,  not_wf,  and_wf,  true_wf,  equiv_rel_true
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  sqequalRule,  cut,  lemma_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  hypothesisEquality,  hypothesis,  independent_isectElimination,  productElimination,  independent_functionElimination,  voidElimination,  lambdaEquality,  unionEquality,  universeEquality

Latex:
\mforall{}P:\mBbbP{}.  (\00D9(P  \mvee{}  (\mneg{}P))  \msubseteq{}r  (\00D9(P)  \mvee{}  \00D9(\mneg{}P)))



Date html generated: 2016_05_14-AM-06_08_53
Last ObjectModification: 2015_12_26-AM-11_48_11

Theory : quot_1


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