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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