Nuprl Lemma : ext-eq_weakening
∀[A,B:Type].  A ≡ B supposing A = B ∈ Type
Proof
Definitions occuring in Statement : 
ext-eq: A ≡ B
, 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
universe: Type
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
uimplies: b supposing a
, 
ext-eq: A ≡ B
, 
and: P ∧ Q
, 
subtype_rel: A ⊆r B
, 
prop: ℙ
Lemmas referenced : 
equal_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
independent_pairFormation, 
lambdaEquality, 
hyp_replacement, 
hypothesisEquality, 
hypothesis, 
equalitySymmetry, 
sqequalRule, 
sqequalHypSubstitution, 
productElimination, 
thin, 
independent_pairEquality, 
axiomEquality, 
instantiate, 
lemma_by_obid, 
isectElimination, 
universeEquality, 
isect_memberEquality, 
because_Cache, 
equalityTransitivity
Latex:
\mforall{}[A,B:Type].    A  \mequiv{}  B  supposing  A  =  B
Date html generated:
2016_05_13-PM-03_19_05
Last ObjectModification:
2015_12_26-AM-09_07_55
Theory : subtype_0
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