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: b supposing a,  uall: ∀[x:A]. B[x],  guard: {T},  so_apply: x[s],  implies: P ⇒ Q,  apply: f a,  base: Base,  universe: Type,  equal: s = t ∈ T
Definitions unfolded in proof :  guard: {T},  uall: ∀[x:A]. B[x],  member: t ∈ T,  uimplies: b supposing a,  implies: P ⇒ Q,  function-eq: function-eq(A;a.B[a];f;g),  so_lambda: λ2x.t[x],  label: ...$L... t,  so_apply: x[s],  prop: ℙ,  all: ∀x:A. B[x],  and: P ∧ Q,  squash: ↓T,  subtype_rel: A ⊆r 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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