Nuprl Lemma : triple-neg-ext
∀[A:ℙ]. uiff(¬¬¬A;¬A)
Proof
Definitions occuring in Statement : 
uiff: uiff(P;Q)
, 
uall: ∀[x:A]. B[x]
, 
prop: ℙ
, 
not: ¬A
Definitions unfolded in proof : 
member: t ∈ T
, 
triple-neg
Lemmas referenced : 
triple-neg
Rules used in proof : 
introduction, 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
cut, 
instantiate, 
extract_by_obid, 
hypothesis, 
sqequalRule, 
thin, 
sqequalHypSubstitution, 
equalityTransitivity, 
equalitySymmetry
Latex:
\mforall{}[A:\mBbbP{}].  uiff(\mneg{}\mneg{}\mneg{}A;\mneg{}A)
Date html generated:
2018_05_21-PM-00_00_24
Last ObjectModification:
2018_05_19-AM-07_14_04
Theory : core_2
Home
Index