Nuprl Lemma : wfd-tree-induction-ext
∀[A:Type]. ∀[P:wfd-tree(A) ⟶ ℙ].
  (P[w-nil()] 
⇒ (∀f:A ⟶ wfd-tree(A). ((∀a:A. P[f a]) 
⇒ P[mk-wfd-tree(f)])) 
⇒ (∀w:wfd-tree(A). P[w]))
Proof
Definitions occuring in Statement : 
mk-wfd-tree: mk-wfd-tree(f)
, 
w-nil: w-nil()
, 
wfd-tree2: wfd-tree(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
, 
so_lambda: λ2x.t[x]
, 
wfd-tree-induction, 
bool-bar-induction, 
list_induction
Lemmas referenced : 
wfd-tree-induction, 
bool-bar-induction, 
list_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{}[P:wfd-tree(A)  {}\mrightarrow{}  \mBbbP{}].
    (P[w-nil()]
    {}\mRightarrow{}  (\mforall{}f:A  {}\mrightarrow{}  wfd-tree(A).  ((\mforall{}a:A.  P[f  a])  {}\mRightarrow{}  P[mk-wfd-tree(f)]))
    {}\mRightarrow{}  (\mforall{}w:wfd-tree(A).  P[w]))
Date html generated:
2018_05_21-PM-10_18_22
Last ObjectModification:
2018_05_19-PM-04_13_07
Theory : bar!induction
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