Nuprl Lemma : rat-interval-intersection-symm
∀[I,J:ℚInterval].  (I ⋂ J = J ⋂ I ∈ ℚInterval)
Proof
Definitions occuring in Statement : 
rat-interval-intersection: I ⋂ J
, 
rational-interval: ℚInterval
, 
uall: ∀[x:A]. B[x]
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
implies: P 
⇒ Q
, 
rev_implies: P 
⇐ Q
, 
and: P ∧ Q
, 
iff: P 
⇐⇒ Q
, 
guard: {T}
, 
uimplies: b supposing a
, 
subtype_rel: A ⊆r B
, 
true: True
, 
squash: ↓T
, 
rat-interval-intersection: I ⋂ J
, 
rational-interval: ℚInterval
, 
member: t ∈ T
, 
uall: ∀[x:A]. B[x]
Lemmas referenced : 
subtype_rel_self, 
int-subtype-rationals, 
qmul_wf, 
iff_weakening_equal, 
qmin-as-qmax, 
qmin_wf, 
rationals_wf, 
equal_wf, 
qmax-symmetry
Rules used in proof : 
inhabitedIsType, 
isectIsTypeImplies, 
axiomEquality, 
isect_memberEquality_alt, 
minusEquality, 
independent_functionElimination, 
independent_isectElimination, 
equalitySymmetry, 
equalityTransitivity, 
baseClosed, 
imageMemberEquality, 
natural_numberEquality, 
because_Cache, 
imageElimination, 
lambdaEquality_alt, 
applyEquality, 
hypothesis, 
hypothesisEquality, 
isectElimination, 
extract_by_obid, 
independent_pairEquality, 
sqequalRule, 
thin, 
productElimination, 
sqequalHypSubstitution, 
cut, 
introduction, 
isect_memberFormation_alt, 
sqequalReflexivity, 
computationStep, 
sqequalTransitivity, 
sqequalSubstitution
Latex:
\mforall{}[I,J:\mBbbQ{}Interval].    (I  \mcap{}  J  =  J  \mcap{}  I)
Date html generated:
2019_10_29-AM-07_48_26
Last ObjectModification:
2019_10_18-PM-00_48_37
Theory : rationals
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