Nuprl Lemma : fset-distributive
∀[T:Type]. ∀[eq:EqDecider(T)]. ∀[a,b,c:fset(T)].  (a ⋂ b ⋃ c = a ⋂ b ⋃ a ⋂ c ∈ fset(T))
Proof
Definitions occuring in Statement : 
fset-intersection: a ⋂ b, 
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, 
implies: P ⇒ Q, 
prop: ℙ, 
all: ∀x:A. B[x], 
decidable: Dec(P), 
or: P ∨ Q, 
cand: A c∧ B, 
sq_stable: SqStable(P), 
squash: ↓T, 
guard: {T}, 
not: ¬A, 
false: False, 
iff: P ⇐⇒ Q, 
rev_implies: P ⇐ Q
Lemmas referenced : 
member-fset-union, 
member-fset-intersection, 
iff_weakening_uiff, 
iff_transitivity, 
uiff_wf, 
or_wf, 
and_wf, 
sq_stable_from_decidable, 
decidable__fset-member, 
deq_wf, 
fset_wf, 
fset-member_wf, 
fset-member_witness, 
fset-union_wf, 
fset-intersection_wf, 
fset-extensionality
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
lemma_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
hypothesis, 
productElimination, 
independent_isectElimination, 
sqequalRule, 
independent_pairEquality, 
isect_memberEquality, 
because_Cache, 
independent_functionElimination, 
equalityTransitivity, 
equalitySymmetry, 
axiomEquality, 
universeEquality, 
independent_pairFormation, 
dependent_functionElimination, 
unionElimination, 
inlFormation, 
imageMemberEquality, 
baseClosed, 
imageElimination, 
inrFormation, 
voidElimination, 
cumulativity, 
addLevel, 
lambdaFormation, 
orFunctionality
Latex:
\mforall{}[T:Type].  \mforall{}[eq:EqDecider(T)].  \mforall{}[a,b,c:fset(T)].    (a  \mcap{}  b  \mcup{}  c  =  a  \mcap{}  b  \mcup{}  a  \mcap{}  c)
Date html generated:
2016_05_14-PM-03_40_28
Last ObjectModification:
2016_01_14-PM-10_41_01
Theory : finite!sets
Home
Index