Nuprl Lemma : fun-connected-induction

[T:Type]
  ∀f:T ⟶ T
    ∀[R:T ⟶ T ⟶ ℙ]
      ((∀x:T. R[x;x])
       (∀x,y,z:T.  (y is f*(z)  R[y;z]  R[x;z]) supposing ((¬(x y ∈ T)) and (x (f y) ∈ T)))
       {∀x,y:T.  (x is f*(y)  R[x;y])})


Proof




Definitions occuring in Statement :  fun-connected: is f*(x) uimplies: supposing a uall: [x:A]. B[x] prop: guard: {T} so_apply: x[s1;s2] all: x:A. B[x] not: ¬A implies:  Q apply: a function: x:A ⟶ B[x] universe: Type equal: t ∈ T
Definitions unfolded in proof :  guard: {T} uall: [x:A]. B[x] all: x:A. B[x] implies:  Q member: t ∈ T prop: so_lambda: λ2x.t[x] uimplies: supposing a so_apply: x[s1;s2] subtype_rel: A ⊆B so_apply: x[s] and: P ∧ Q not: ¬A fun-path: y=f*(x) via L fun-connected: is f*(x) exists: x:A. B[x] select: L[n] nil: [] it: so_lambda: λ2y.t[x; y] top: Top subtract: m less_than: a < b squash: T less_than': less_than'(a;b) false: False uiff: uiff(P;Q) decidable: Dec(P) or: P ∨ Q
Lemmas referenced :  all_wf isect_wf equal_wf not_wf fun-connected_wf fun-path_wf nil_wf less_than_wf length_wf cons_wf list_induction list_wf length_of_nil_lemma stuck-spread base_wf fun-path-cons decidable__lt
Rules used in proof :  sqequalSubstitution sqequalRule sqequalReflexivity sqequalTransitivity computationStep isect_memberFormation lambdaFormation cut introduction extract_by_obid sqequalHypSubstitution isectElimination thin cumulativity hypothesisEquality lambdaEquality because_Cache applyEquality functionExtensionality hypothesis functionEquality universeEquality natural_numberEquality productEquality independent_isectElimination productElimination independent_functionElimination baseClosed isect_memberEquality voidElimination voidEquality imageElimination rename equalitySymmetry hyp_replacement applyLambdaEquality dependent_functionElimination unionElimination dependent_pairFormation

Latex:
\mforall{}[T:Type]
    \mforall{}f:T  {}\mrightarrow{}  T
        \mforall{}[R:T  {}\mrightarrow{}  T  {}\mrightarrow{}  \mBbbP{}]
            ((\mforall{}x:T.  R[x;x])
            {}\mRightarrow{}  (\mforall{}x,y,z:T.    (y  is  f*(z)  {}\mRightarrow{}  R[y;z]  {}\mRightarrow{}  R[x;z])  supposing  ((\mneg{}(x  =  y))  and  (x  =  (f  y))))
            {}\mRightarrow{}  \{\mforall{}x,y:T.    (x  is  f*(y)  {}\mRightarrow{}  R[x;y])\})



Date html generated: 2018_05_21-PM-07_44_06
Last ObjectModification: 2017_07_26-PM-05_21_51

Theory : general


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