Nuprl Lemma : not_functionality_wrt_implies
∀[P,Q:ℙ].  {(¬P) ⇒ (¬Q)} supposing {P ⇐ Q}
Proof
Definitions occuring in Statement : 
uimplies: b supposing a, 
uall: ∀[x:A]. B[x], 
prop: ℙ, 
guard: {T}, 
not: ¬A, 
rev_implies: P ⇐ Q, 
implies: P ⇒ Q
Definitions unfolded in proof : 
not: ¬A, 
guard: {T}, 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
uimplies: b supposing a, 
implies: P ⇒ Q, 
false: False, 
prop: ℙ, 
rev_implies: P ⇐ Q
Lemmas referenced : 
false_wf, 
rev_implies_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalRule, 
sqequalReflexivity, 
sqequalTransitivity, 
computationStep, 
Error :isect_memberFormation_alt, 
introduction, 
cut, 
lambdaFormation, 
hypothesis, 
hypothesisEquality, 
functionEquality, 
extract_by_obid, 
sqequalHypSubstitution, 
lambdaEquality, 
dependent_functionElimination, 
thin, 
because_Cache, 
cumulativity, 
Error :functionIsType, 
Error :universeIsType, 
isect_memberEquality, 
isectElimination, 
equalityTransitivity, 
equalitySymmetry, 
Error :inhabitedIsType, 
voidElimination, 
universeEquality, 
independent_functionElimination
Latex:
\mforall{}[P,Q:\mBbbP{}].    \{(\mneg{}P)  {}\mRightarrow{}  (\mneg{}Q)\}  supposing  \{P  \mLeftarrow{}{}  Q\}
Date html generated:
2019_06_20-AM-11_17_08
Last ObjectModification:
2018_09_26-AM-10_24_39
Theory : core_2
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