Nuprl Lemma : decidable__equal_fset
∀[T:Type]. ((∀x,y:T.  Dec(x = y ∈ T)) ⇒ (∀xs,ys:fset(T).  Dec(xs = ys ∈ fset(T))))
Proof
Definitions occuring in Statement : 
fset: fset(T), 
decidable: Dec(P), 
uall: ∀[x:A]. B[x], 
all: ∀x:A. B[x], 
implies: P ⇒ Q, 
universe: Type, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
implies: P ⇒ Q, 
all: ∀x:A. B[x], 
member: t ∈ T, 
prop: ℙ, 
so_lambda: λ2x.t[x], 
so_apply: x[s], 
iff: P ⇐⇒ Q, 
and: P ∧ Q, 
uimplies: b supposing a, 
f-subset: xs ⊆ ys, 
rev_implies: P ⇐ Q
Lemmas referenced : 
fset_wf, 
all_wf, 
decidable_wf, 
equal_wf, 
mk_deq_wf, 
f-subset_weakening, 
fset-member_witness, 
fset-member_wf, 
f-subset_antisymmetry, 
and_wf, 
f-subset_wf, 
decidable_functionality, 
decidable__and2, 
decidable__f-subset
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
lambdaFormation, 
cut, 
lemma_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
hypothesis, 
sqequalRule, 
lambdaEquality, 
universeEquality, 
rename, 
introduction, 
independent_pairFormation, 
independent_isectElimination, 
dependent_functionElimination, 
isect_memberEquality, 
independent_functionElimination, 
equalityTransitivity, 
equalitySymmetry, 
because_Cache, 
productElimination
Latex:
\mforall{}[T:Type].  ((\mforall{}x,y:T.    Dec(x  =  y))  {}\mRightarrow{}  (\mforall{}xs,ys:fset(T).    Dec(xs  =  ys)))
Date html generated:
2016_05_14-PM-03_41_41
Last ObjectModification:
2015_12_26-PM-06_40_20
Theory : finite!sets
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