Nuprl Lemma : setsubset_functionality
∀a,b,a',b':coSet{i:l}.  (seteq(a;a') ⇒ seteq(b;b') ⇒ ((a ⊆ b) ⇐⇒ (a' ⊆ b')))
Proof
Definitions occuring in Statement : 
setsubset: (a ⊆ b), 
seteq: seteq(s1;s2), 
coSet: coSet{i:l}, 
all: ∀x:A. B[x], 
iff: P ⇐⇒ Q, 
implies: P ⇒ Q
Definitions unfolded in proof : 
guard: {T}, 
so_apply: x[s], 
so_lambda: λ2x.t[x], 
prop: ℙ, 
uall: ∀[x:A]. B[x], 
rev_implies: P ⇐ Q, 
member: t ∈ T, 
and: P ∧ Q, 
iff: P ⇐⇒ Q, 
implies: P ⇒ Q, 
all: ∀x:A. B[x]
Lemmas referenced : 
seteq_weakening, 
setmem_functionality, 
seteq_wf, 
setmem_wf, 
coSet_wf, 
all_wf, 
iff_wf, 
setsubset_wf, 
setsubset-iff
Rules used in proof : 
impliesLevelFunctionality, 
allLevelFunctionality, 
allFunctionality, 
because_Cache, 
functionEquality, 
lambdaEquality, 
sqequalRule, 
instantiate, 
isectElimination, 
cumulativity, 
independent_functionElimination, 
hypothesis, 
hypothesisEquality, 
dependent_functionElimination, 
extract_by_obid, 
introduction, 
impliesFunctionality, 
independent_pairFormation, 
thin, 
productElimination, 
sqequalHypSubstitution, 
addLevel, 
cut, 
lambdaFormation, 
sqequalReflexivity, 
computationStep, 
sqequalTransitivity, 
sqequalSubstitution
Latex:
\mforall{}a,b,a',b':coSet\{i:l\}.    (seteq(a;a')  {}\mRightarrow{}  seteq(b;b')  {}\mRightarrow{}  ((a  \msubseteq{}  b)  \mLeftarrow{}{}\mRightarrow{}  (a'  \msubseteq{}  b')))
Date html generated:
2018_07_29-AM-10_01_21
Last ObjectModification:
2018_07_20-PM-06_23_00
Theory : constructive!set!theory
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