Nuprl Lemma : fset-singletons-equal
∀[T:Type]. ∀[eq:EqDecider(T)]. ∀[x,y:T].  uiff({x} = {y} ∈ fset(T);x = y ∈ T)
Proof
Definitions occuring in Statement : 
fset-singleton: {x}
, 
fset: fset(T)
, 
deq: EqDecider(T)
, 
uiff: uiff(P;Q)
, 
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
, 
prop: ℙ
Lemmas referenced : 
equal_wf, 
fset_wf, 
fset-singleton_wf, 
and_wf, 
deq_wf, 
member-fset-singleton, 
fset-member_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
independent_pairFormation, 
hypothesis, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
cumulativity, 
hypothesisEquality, 
equalitySymmetry, 
dependent_set_memberEquality, 
applyEquality, 
lambdaEquality, 
setElimination, 
rename, 
productElimination, 
setEquality, 
sqequalRule, 
independent_pairEquality, 
isect_memberEquality, 
axiomEquality, 
because_Cache, 
equalityTransitivity, 
independent_isectElimination, 
hyp_replacement, 
Error :applyLambdaEquality
Latex:
\mforall{}[T:Type].  \mforall{}[eq:EqDecider(T)].  \mforall{}[x,y:T].    uiff(\{x\}  =  \{y\};x  =  y)
Date html generated:
2016_10_21-AM-10_44_10
Last ObjectModification:
2016_07_12-AM-05_51_01
Theory : finite!sets
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