Nuprl Lemma : stable__function_equal

[A,B:Type]. ∀[f,g:A ⟶ B].  Stable{f g ∈ (A ⟶ B)} supposing ∀x:A. Stable{(f x) (g x) ∈ B}


Proof




Definitions occuring in Statement :  stable: Stable{P} uimplies: supposing a uall: [x:A]. B[x] all: x:A. B[x] apply: a function: x:A ⟶ B[x] universe: Type equal: t ∈ T
Definitions unfolded in proof :  stable: Stable{P} uall: [x:A]. B[x] member: t ∈ T uimplies: supposing a all: x:A. B[x] not: ¬A implies:  Q and: P ∧ Q prop: false: False so_lambda: λ2x.t[x] so_apply: x[s]
Lemmas referenced :  isect_wf all_wf not_wf equal_wf and_wf
Rules used in proof :  sqequalSubstitution sqequalRule sqequalReflexivity sqequalTransitivity computationStep isect_memberFormation introduction cut functionExtensionality hypothesis sqequalHypSubstitution dependent_functionElimination thin hypothesisEquality independent_isectElimination lambdaFormation independent_functionElimination equalitySymmetry dependent_set_memberEquality independent_pairFormation lemma_by_obid isectElimination functionEquality applyEquality lambdaEquality setElimination rename productElimination setEquality voidElimination isect_memberEquality axiomEquality because_Cache equalityTransitivity universeEquality

Latex:
\mforall{}[A,B:Type].  \mforall{}[f,g:A  {}\mrightarrow{}  B].    Stable\{f  =  g\}  supposing  \mforall{}x:A.  Stable\{(f  x)  =  (g  x)\}



Date html generated: 2016_05_13-PM-03_09_31
Last ObjectModification: 2016_01_06-PM-05_27_14

Theory : core_2


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