Nuprl Lemma : ite_wf

[b:𝔹]. ∀[T:Type]. ∀[x:T supposing ↑b]. ∀[y:T supposing ¬↑b].  (ite(b;x;y) ∈ T)


Proof




Definitions occuring in Statement :  ite: ite(b;x;y) assert: b bool: 𝔹 uimplies: supposing a uall: [x:A]. B[x] not: ¬A member: t ∈ T universe: Type
Definitions unfolded in proof :  ite: ite(b;x;y) bool: 𝔹 assert: b ifthenelse: if then else fi  member: t ∈ T uimplies: supposing a uall: [x:A]. B[x] prop: true: True not: ¬A implies:  Q false: False
Lemmas referenced :  not_wf assert_wf bool_wf false_wf
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity sqequalHypSubstitution unionElimination thin sqequalRule isectEquality cut lemma_by_obid isectElimination hypothesisEquality hypothesis because_Cache universeEquality isect_memberFormation introduction axiomEquality equalityTransitivity equalitySymmetry isect_memberEquality independent_isectElimination natural_numberEquality lambdaEquality voidElimination lambdaFormation

Latex:
\mforall{}[b:\mBbbB{}].  \mforall{}[T:Type].  \mforall{}[x:T  supposing  \muparrow{}b].  \mforall{}[y:T  supposing  \mneg{}\muparrow{}b].    (ite(b;x;y)  \mmember{}  T)



Date html generated: 2016_05_15-PM-03_26_22
Last ObjectModification: 2015_12_27-PM-01_07_25

Theory : general


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