Nuprl Lemma : subtype_rel_transitivity
∀[A,B,C:Type].  (A ⊆r C) supposing ((B ⊆r C) and (A ⊆r B))
Proof
Definitions occuring in Statement : 
uimplies: b supposing a
, 
subtype_rel: A ⊆r B
, 
uall: ∀[x:A]. B[x]
, 
universe: Type
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
uimplies: b supposing a
, 
subtype_rel: A ⊆r B
Lemmas referenced : 
subtype_rel_wf, 
istype-universe
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation_alt, 
introduction, 
cut, 
sqequalRule, 
axiomEquality, 
hypothesis, 
universeIsType, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
isect_memberEquality_alt, 
isectIsTypeImplies, 
inhabitedIsType, 
instantiate, 
universeEquality, 
lambdaEquality_alt, 
applyEquality
Latex:
\mforall{}[A,B,C:Type].    (A  \msubseteq{}r  C)  supposing  ((B  \msubseteq{}r  C)  and  (A  \msubseteq{}r  B))
Date html generated:
2020_05_19-PM-09_35_10
Last ObjectModification:
2019_12_05-PM-00_02_01
Theory : subtype_0
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