Nuprl Lemma : W-induction1-extract
∀[A:Type]. ∀[B:A ⟶ Type]. ∀[Q:W(A;a.B[a]) ⟶ ℙ].
  ((∀a:A. ∀f:B[a] ⟶ W(A;a.B[a]).  ((∀b:B[a]. Q[f b]) 
⇒ Q[Wsup(a;f)])) 
⇒ (∀w:W(A;a.B[a]). Q[w]))
Proof
Definitions occuring in Statement : 
Wsup: Wsup(a;b)
, 
W: W(A;a.B[a])
, 
uall: ∀[x:A]. B[x]
, 
prop: ℙ
, 
so_apply: x[s]
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
apply: f a
, 
function: x:A ⟶ B[x]
, 
universe: Type
Definitions unfolded in proof : 
member: t ∈ T
, 
it: ⋅
, 
so_lambda: so_lambda(x,y,z.t[x; y; z])
, 
so_apply: x[s1;s2;s3]
, 
pW-rec: pW-rec, 
genrec-ap: genrec-ap, 
W-induction1, 
param-W-induction
Lemmas referenced : 
W-induction1, 
param-W-induction
Rules used in proof : 
introduction, 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
cut, 
instantiate, 
extract_by_obid, 
hypothesis, 
sqequalRule, 
thin, 
sqequalHypSubstitution, 
equalityTransitivity, 
equalitySymmetry
Latex:
\mforall{}[A:Type].  \mforall{}[B:A  {}\mrightarrow{}  Type].  \mforall{}[Q:W(A;a.B[a])  {}\mrightarrow{}  \mBbbP{}].
    ((\mforall{}a:A.  \mforall{}f:B[a]  {}\mrightarrow{}  W(A;a.B[a]).    ((\mforall{}b:B[a].  Q[f  b])  {}\mRightarrow{}  Q[Wsup(a;f)]))  {}\mRightarrow{}  (\mforall{}w:W(A;a.B[a]).  Q[w]))
Date html generated:
2018_05_21-PM-00_05_36
Last ObjectModification:
2018_05_19-AM-07_00_36
Theory : co-recursion
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