Nuprl Lemma : wfd-tree-rec_wf
∀[X,T:Type]. ∀[b:X]. ∀[F:(T ⟶ X) ⟶ X]. ∀[t:wfd-tree(T)].  (wfd-tree-rec(b;r.F[r];t) ∈ X)
Proof
Definitions occuring in Statement : 
wfd-tree-rec: wfd-tree-rec(b;r.F[r];t), 
wfd-tree: wfd-tree(T), 
uall: ∀[x:A]. B[x], 
so_apply: x[s], 
member: t ∈ T, 
function: x:A ⟶ B[x], 
universe: Type
Definitions unfolded in proof : 
wfd-tree: wfd-tree(T), 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
wfd-tree-rec: wfd-tree-rec(b;r.F[r];t), 
so_lambda: λ2x.t[x], 
all: ∀x:A. B[x], 
implies: P ⇒ Q, 
bool: 𝔹, 
unit: Unit, 
it: ⋅, 
btrue: tt, 
ifthenelse: if b then t else f fi , 
uiff: uiff(P;Q), 
and: P ∧ Q, 
uimplies: b supposing a, 
bfalse: ff, 
prop: ℙ, 
so_apply: x[s], 
so_lambda: so_lambda(x,y,z.t[x; y; z]), 
exists: ∃x:A. B[x], 
or: P ∨ Q, 
sq_type: SQType(T), 
guard: {T}, 
bnot: ¬bb, 
assert: ↑b, 
false: False, 
so_apply: x[s1;s2;s3]
Lemmas referenced : 
W-rec_wf, 
bool_wf, 
eqtt_to_assert, 
equal_wf, 
eqff_to_assert, 
bool_cases_sqequal, 
subtype_base_sq, 
bool_subtype_base, 
assert-bnot, 
W_wf, 
ifthenelse_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalRule, 
sqequalReflexivity, 
sqequalTransitivity, 
computationStep, 
isect_memberFormation, 
introduction, 
cut, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
cumulativity, 
hypothesisEquality, 
hypothesis, 
lambdaEquality, 
lambdaFormation, 
unionElimination, 
equalityElimination, 
productElimination, 
independent_isectElimination, 
voidEquality, 
equalityTransitivity, 
equalitySymmetry, 
dependent_functionElimination, 
independent_functionElimination, 
because_Cache, 
dependent_pairFormation, 
promote_hyp, 
instantiate, 
voidElimination, 
applyEquality, 
functionExtensionality, 
functionEquality, 
axiomEquality, 
universeEquality, 
isect_memberEquality
Latex:
\mforall{}[X,T:Type].  \mforall{}[b:X].  \mforall{}[F:(T  {}\mrightarrow{}  X)  {}\mrightarrow{}  X].  \mforall{}[t:wfd-tree(T)].    (wfd-tree-rec(b;r.F[r];t)  \mmember{}  X)
Date html generated:
2017_04_14-AM-07_45_11
Last ObjectModification:
2017_02_27-PM-03_16_11
Theory : co-recursion
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