Nuprl Lemma : is-above-subtype
∀[A,B:Type].  ∀[a:A]. ∀[z:Base].  (is-above(A;a;z) 
⇒ is-above(B;a;z)) supposing A ⊆r B
Proof
Definitions occuring in Statement : 
is-above: is-above(T;a;z)
, 
uimplies: b supposing a
, 
subtype_rel: A ⊆r B
, 
uall: ∀[x:A]. B[x]
, 
implies: P 
⇒ Q
, 
base: Base
, 
universe: Type
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
uimplies: b supposing a
, 
member: t ∈ T
, 
subtype_rel: A ⊆r B
, 
implies: P 
⇒ Q
, 
is-above: is-above(T;a;z)
, 
exists: ∃x:A. B[x]
, 
and: P ∧ Q
, 
prop: ℙ
, 
cand: A c∧ B
, 
guard: {T}
Lemmas referenced : 
is-above_wf, 
base_wf, 
subtype_rel_wf, 
equal_functionality_wrt_subtype_rel2, 
equal-wf-base-T, 
sqle_wf_base
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
cut, 
introduction, 
sqequalRule, 
axiomEquality, 
hypothesis, 
thin, 
rename, 
lambdaFormation, 
sqequalHypSubstitution, 
productElimination, 
lemma_by_obid, 
isectElimination, 
hypothesisEquality, 
universeEquality, 
dependent_pairFormation, 
equalityTransitivity, 
equalitySymmetry, 
independent_isectElimination, 
independent_functionElimination, 
independent_pairFormation, 
productEquality, 
applyEquality
Latex:
\mforall{}[A,B:Type].    \mforall{}[a:A].  \mforall{}[z:Base].    (is-above(A;a;z)  {}\mRightarrow{}  is-above(B;a;z))  supposing  A  \msubseteq{}r  B
Date html generated:
2016_05_13-PM-04_13_02
Last ObjectModification:
2015_12_26-AM-11_11_22
Theory : subtype_1
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