Nuprl Lemma : subtype-value-type
∀[A,B:Type].  (value-type(A)) supposing (value-type(B) and (A ⊆r B))
Proof
Definitions occuring in Statement : 
value-type: value-type(T)
, 
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
, 
value-type: value-type(T)
, 
sq_stable: SqStable(P)
, 
implies: P 
⇒ Q
, 
all: ∀x:A. B[x]
, 
has-value: (a)↓
, 
subtype_rel: A ⊆r B
, 
prop: ℙ
, 
squash: ↓T
Lemmas referenced : 
sq_stable__has-value, 
value-type-has-value, 
equal_wf, 
equal-wf-base, 
base_wf, 
value-type_wf, 
subtype_rel_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
hypothesis, 
independent_functionElimination, 
equalityTransitivity, 
equalitySymmetry, 
lambdaFormation, 
applyEquality, 
sqequalRule, 
independent_isectElimination, 
dependent_functionElimination, 
imageMemberEquality, 
baseClosed, 
imageElimination, 
because_Cache, 
isect_memberEquality, 
axiomSqleEquality, 
cumulativity, 
universeEquality
Latex:
\mforall{}[A,B:Type].    (value-type(A))  supposing  (value-type(B)  and  (A  \msubseteq{}r  B))
Date html generated:
2017_04_14-AM-07_15_47
Last ObjectModification:
2017_02_27-PM-02_51_00
Theory : call!by!value_1
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