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: so_apply: x[s] all: x:A. B[x] implies:  Q apply: 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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