Nuprl Lemma : not-quotient-true
∀[P:ℙ]. (¬⇃(P)
⇐⇒ ¬P)
Proof
Definitions occuring in Statement :
quotient: x,y:A//B[x; y]
,
uall: ∀[x:A]. B[x]
,
prop: ℙ
,
iff: P
⇐⇒ Q
,
not: ¬A
,
true: True
Definitions unfolded in proof :
uall: ∀[x:A]. B[x]
,
member: t ∈ T
,
iff: P
⇐⇒ Q
,
and: P ∧ Q
,
implies: P
⇒ Q
,
not: ¬A
,
false: False
,
prop: ℙ
,
so_lambda: λ2x y.t[x; y]
,
so_apply: x[s1;s2]
,
uimplies: b supposing a
,
rev_implies: P
⇐ Q
,
quotient: x,y:A//B[x; y]
,
cand: A c∧ B
Lemmas referenced :
trivial-quotient-true,
istype-universe,
not_wf,
quotient_wf,
true_wf,
equiv_rel_true,
false_wf
Rules used in proof :
sqequalSubstitution,
sqequalTransitivity,
computationStep,
sqequalReflexivity,
Error :isect_memberFormation_alt,
introduction,
cut,
independent_pairFormation,
Error :lambdaFormation_alt,
thin,
sqequalHypSubstitution,
independent_functionElimination,
extract_by_obid,
isectElimination,
hypothesisEquality,
hypothesis,
voidElimination,
Error :universeIsType,
cumulativity,
sqequalRule,
Error :lambdaEquality_alt,
Error :inhabitedIsType,
independent_isectElimination,
because_Cache,
productElimination,
independent_pairEquality,
dependent_functionElimination,
Error :functionIsTypeImplies,
universeEquality,
pointwiseFunctionality,
pertypeElimination,
Error :productIsType,
Error :equalityIsType4,
equalityTransitivity,
equalitySymmetry
Latex:
\mforall{}[P:\mBbbP{}]. (\mneg{}\00D9(P) \mLeftarrow{}{}\mRightarrow{} \mneg{}P)
Date html generated:
2019_06_20-PM-00_32_37
Last ObjectModification:
2018_10_06-PM-04_17_45
Theory : quot_1
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