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: y is f*(x),  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  prop: ℙ,  guard: {T},  so_apply: x[s1;s2],  all: ∀x:A. B[x],  not: ¬A,  implies: P ⇒ Q,  apply: f a,  function: x:A ⟶ B[x],  universe: Type,  equal: s = t ∈ T
Definitions unfolded in proof :  guard: {T},  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  implies: P ⇒ Q,  member: t ∈ T,  prop: ℙ,  so_lambda: λ2x.t[x],  uimplies: b supposing a,  so_apply: x[s1;s2],  subtype_rel: A ⊆r B,  so_apply: x[s],  and: P ∧ Q,  not: ¬A,  fun-path: y=f*(x) via L,  fun-connected: y is f*(x),  exists: ∃x:A. B[x],  select: L[n],  nil: [],  it: ⋅,  so_lambda: λ2x y.t[x; y],  top: Top,  subtract: n - 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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