Nuprl Lemma : decidable__list-closed2-ext
∀[T:Type]. ∀L:T List. ∀f:T ⟶ (T List). ∀d:EqDecider(T).  Dec(list-closed(T;L;f))
Proof
Definitions occuring in Statement : 
list-closed: list-closed(T;L;f), 
list: T List, 
deq: EqDecider(T), 
decidable: Dec(P), 
uall: ∀[x:A]. B[x], 
all: ∀x:A. B[x], 
function: x:A ⟶ B[x], 
universe: Type
Definitions unfolded in proof : 
member: t ∈ T, 
deq-witness: deq-witness(eq), 
ifthenelse: if b then t else f fi , 
list_ind: list_ind, 
bottom: ⊥, 
genrec-ap: genrec-ap, 
spreadn: spread3, 
decidable__list-closed2, 
decidable__list-closed, 
decidable-equal-deq, 
decidable__l_all, 
decidable__l_member, 
list_induction, 
decidable_functionality, 
nil_member, 
decidable__false, 
cons_member, 
decidable__or, 
iff_preserves_decidability, 
any: any x, 
decidable__assert, 
uall: ∀[x:A]. B[x], 
so_lambda: so_lambda(x,y,z,w.t[x; y; z; w]), 
so_apply: x[s1;s2;s3;s4], 
so_lambda: λ2x.t[x], 
top: Top, 
so_apply: x[s], 
uimplies: b supposing a
Lemmas referenced : 
decidable__list-closed2, 
lifting-strict-decide, 
istype-void, 
strict4-decide, 
decidable__list-closed, 
decidable-equal-deq, 
decidable__l_all, 
decidable__l_member, 
list_induction, 
decidable_functionality, 
nil_member, 
decidable__false, 
cons_member, 
decidable__or, 
iff_preserves_decidability, 
decidable__assert
Rules used in proof : 
introduction, 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
cut, 
instantiate, 
extract_by_obid, 
hypothesis, 
sqequalRule, 
thin, 
sqequalHypSubstitution, 
equalityTransitivity, 
equalitySymmetry, 
isectElimination, 
baseClosed, 
Error :isect_memberEquality_alt, 
voidElimination, 
independent_isectElimination
Latex:
\mforall{}[T:Type].  \mforall{}L:T  List.  \mforall{}f:T  {}\mrightarrow{}  (T  List).  \mforall{}d:EqDecider(T).    Dec(list-closed(T;L;f))
Date html generated:
2019_06_20-PM-01_51_21
Last ObjectModification:
2019_05_13-PM-03_38_11
Theory : list_1
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