Nuprl Lemma : empty-fset-union
∀[T:Type]. ∀[eq:EqDecider(T)]. ∀[s:fset(T)].  ({} ⋃ s = s ∈ fset(T))
Proof
Definitions occuring in Statement : 
empty-fset: {}, 
fset-union: x ⋃ y, 
fset: fset(T), 
deq: EqDecider(T), 
uall: ∀[x:A]. B[x], 
universe: Type, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
uiff: uiff(P;Q), 
and: P ∧ Q, 
uimplies: b supposing a, 
all: ∀x:A. B[x], 
top: Top, 
or: P ∨ Q, 
false: False, 
implies: P ⇒ Q, 
prop: ℙ, 
guard: {T}, 
iff: P ⇐⇒ Q, 
rev_implies: P ⇐ Q
Lemmas referenced : 
fset-extensionality, 
fset-union_wf, 
empty-fset_wf, 
fset_wf, 
deq_wf, 
mem_empty_lemma, 
fset-member_witness, 
or_wf, 
false_wf, 
fset-member_wf, 
member-fset-union, 
uiff_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
lemma_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
hypothesis, 
productElimination, 
independent_isectElimination, 
sqequalRule, 
isect_memberEquality, 
axiomEquality, 
because_Cache, 
universeEquality, 
dependent_functionElimination, 
voidElimination, 
voidEquality, 
independent_pairFormation, 
unionElimination, 
independent_functionElimination, 
rename, 
inrFormation, 
addLevel, 
cumulativity, 
independent_pairEquality, 
equalityTransitivity, 
equalitySymmetry
Latex:
\mforall{}[T:Type].  \mforall{}[eq:EqDecider(T)].  \mforall{}[s:fset(T)].    (\{\}  \mcup{}  s  =  s)
Date html generated:
2016_05_14-PM-03_40_39
Last ObjectModification:
2015_12_26-PM-06_40_48
Theory : finite!sets
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