Nuprl Lemma : function-eq-implies

[A:Type]. ∀[B:Base].
  ∀[f,g:Base].  (function-eq(A;a.B[a];f;g)  {∀[a:A]. ((f a) (g a) ∈ B[a])}) 
  supposing base-type-family{i:l}(A;a.B[a])


Proof




Definitions occuring in Statement :  function-eq: function-eq(A;a.B[a];f;g) base-type-family: base-type-family{i:l}(A;a.B[a]) uimplies: supposing a uall: [x:A]. B[x] guard: {T} so_apply: x[s] implies:  Q apply: a base: Base universe: Type equal: t ∈ T
Definitions unfolded in proof :  guard: {T} uall: [x:A]. B[x] member: t ∈ T uimplies: supposing a implies:  Q function-eq: function-eq(A;a.B[a];f;g) so_lambda: λ2x.t[x] label: ...$L... t so_apply: x[s] prop: all: x:A. B[x] and: P ∧ Q squash: T subtype_rel: A ⊆B true: True
Lemmas referenced :  function-eq_wf base_wf base-type-family_wf base-type-family-implies and_wf equal_wf squash_wf true_wf
Rules used in proof :  sqequalSubstitution sqequalRule sqequalReflexivity sqequalTransitivity computationStep isect_memberFormation introduction cut lambdaFormation sqequalHypSubstitution hypothesis hypothesisEquality extract_by_obid isectElimination thin cumulativity baseApply closedConclusion baseClosed independent_isectElimination lambdaEquality dependent_functionElimination isect_memberEquality axiomEquality because_Cache equalityTransitivity equalitySymmetry universeEquality pointwiseFunctionality dependent_set_memberEquality independent_pairFormation applyLambdaEquality setElimination rename productElimination applyEquality imageElimination hyp_replacement natural_numberEquality imageMemberEquality

Latex:
\mforall{}[A:Type].  \mforall{}[B:Base].
    \mforall{}[f,g:Base].    (function-eq(A;a.B[a];f;g)  {}\mRightarrow{}  \{\mforall{}[a:A].  ((f  a)  =  (g  a))\}) 
    supposing  base-type-family\{i:l\}(A;a.B[a])



Date html generated: 2017_04_14-AM-07_29_12
Last ObjectModification: 2017_02_27-PM-02_57_09

Theory : per!type


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