Nuprl Lemma : all-union

[A,B:Type].  ∀P:(A B) ⟶ ℙ(∀x:A B. P[x] ⇐⇒ (∀a:A. P[inl a]) ∧ (∀b:B. P[inr ]))


Proof




Definitions occuring in Statement :  uall: [x:A]. B[x] prop: so_apply: x[s] all: x:A. B[x] iff: ⇐⇒ Q and: P ∧ Q function: x:A ⟶ B[x] inr: inr  inl: inl x union: left right universe: Type
Definitions unfolded in proof :  uall: [x:A]. B[x] all: x:A. B[x] iff: ⇐⇒ Q and: P ∧ Q implies:  Q member: t ∈ T prop: so_lambda: λ2x.t[x] so_apply: x[s] rev_implies:  Q guard: {T}
Lemmas referenced :  all_wf and_wf
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation lambdaFormation independent_pairFormation hypothesisEquality cut lemma_by_obid sqequalHypSubstitution isectElimination thin unionEquality sqequalRule lambdaEquality applyEquality hypothesis productElimination unionElimination inlEquality inrEquality functionEquality cumulativity universeEquality dependent_functionElimination

Latex:
\mforall{}[A,B:Type].    \mforall{}P:(A  +  B)  {}\mrightarrow{}  \mBbbP{}.  (\mforall{}x:A  +  B.  P[x]  \mLeftarrow{}{}\mRightarrow{}  (\mforall{}a:A.  P[inl  a])  \mwedge{}  (\mforall{}b:B.  P[inr  b  ]))



Date html generated: 2016_05_15-PM-03_24_39
Last ObjectModification: 2015_12_27-PM-01_06_08

Theory : general


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