Nuprl Lemma : wellfounded_functionality_wrt_implies

∀[T1,T2:Type]. ∀[r1:T1 ⟶ T1 ⟶ ℙ]. ∀[r2:T2 ⟶ T2 ⟶ ℙ].
  (∀x,y:T1.  {r1[x;y] ⇐ r2[x;y]}) ⇒ {WellFnd{i}(T1;x,y.r1[x;y]) ⇒ WellFnd{i}(T2;x,y.r2[x;y])} 
  supposing T1 = T2 ∈ Type


Proof




Definitions occuring in Statement :  wellfounded: WellFnd{i}(A;x,y.R[x; y]),  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  prop: ℙ,  guard: {T},  so_apply: x[s1;s2],  all: ∀x:A. B[x],  rev_implies: P ⇐ Q,  implies: P ⇒ Q,  function: x:A ⟶ B[x],  universe: Type,  equal: s = t ∈ T
Definitions unfolded in proof :  wellfounded: WellFnd{i}(A;x,y.R[x; y]),  guard: {T},  uall: ∀[x:A]. B[x],  uimplies: b supposing a,  member: t ∈ T,  implies: P ⇒ Q,  prop: ℙ,  so_lambda: λ2x.t[x],  so_apply: x[s1;s2],  so_apply: x[s],  squash: ↓T,  true: True,  all: ∀x:A. B[x],  subtype_rel: A ⊆r B,  rev_implies: P ⇐ Q
Lemmas referenced :  all_wf,  uall_wf,  rev_implies_wf,  equal_wf
Rules used in proof :  sqequalSubstitution,  sqequalRule,  sqequalReflexivity,  sqequalTransitivity,  computationStep,  isect_memberFormation,  cut,  introduction,  axiomEquality,  hypothesis,  thin,  rename,  lambdaFormation,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  cumulativity,  hypothesisEquality,  lambdaEquality,  functionEquality,  applyEquality,  functionExtensionality,  universeEquality,  instantiate,  because_Cache,  hyp_replacement,  equalitySymmetry,  Error :applyLambdaEquality,  imageElimination,  natural_numberEquality,  imageMemberEquality,  baseClosed,  independent_functionElimination,  dependent_functionElimination

Latex:
\mforall{}[T1,T2:Type].  \mforall{}[r1:T1  {}\mrightarrow{}  T1  {}\mrightarrow{}  \mBbbP{}].  \mforall{}[r2:T2  {}\mrightarrow{}  T2  {}\mrightarrow{}  \mBbbP{}].
    (\mforall{}x,y:T1.    \{r1[x;y]  \mLeftarrow{}{}  r2[x;y]\})  {}\mRightarrow{}  \{WellFnd\{i\}(T1;x,y.r1[x;y])  {}\mRightarrow{}  WellFnd\{i\}(T2;x,y.r2[x;y])\} 
    supposing  T1  =  T2



Date html generated: 2016_10_21-AM-09_35_54
Last ObjectModification: 2016_07_12-AM-05_00_01

Theory : well_fnd


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