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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