Nuprl Lemma : subtype_rel_not
∀[P,Q:ℙ].  (¬P) ⊆r (¬Q) supposing Q 
⇒ (↓P)
Proof
Definitions occuring in Statement : 
uimplies: b supposing a
, 
subtype_rel: A ⊆r B
, 
uall: ∀[x:A]. B[x]
, 
prop: ℙ
, 
not: ¬A
, 
squash: ↓T
, 
implies: P 
⇒ Q
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
uimplies: b supposing a
, 
not: ¬A
, 
false: False
, 
implies: P 
⇒ Q
, 
subtype_rel: A ⊆r B
, 
prop: ℙ
, 
guard: {T}
, 
squash: ↓T
Lemmas referenced : 
squash_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
lambdaEquality, 
functionEquality, 
sqequalHypSubstitution, 
sqequalRule, 
hypothesisEquality, 
voidEquality, 
axiomEquality, 
hypothesis, 
lemma_by_obid, 
isectElimination, 
thin, 
isect_memberEquality, 
because_Cache, 
equalityTransitivity, 
equalitySymmetry, 
universeEquality, 
functionExtensionality, 
independent_functionElimination, 
imageElimination, 
voidElimination
Latex:
\mforall{}[P,Q:\mBbbP{}].    (\mneg{}P)  \msubseteq{}r  (\mneg{}Q)  supposing  Q  {}\mRightarrow{}  (\mdownarrow{}P)
Date html generated:
2016_05_13-PM-03_18_57
Last ObjectModification:
2015_12_26-AM-09_08_05
Theory : subtype_0
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