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: iff: ⇐⇒ Q not: ¬A true: True
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T iff: ⇐⇒ Q and: P ∧ Q implies:  Q not: ¬A false: False prop: so_lambda: λ2y.t[x; y] so_apply: x[s1;s2] uimplies: supposing a rev_implies:  Q quotient: x,y:A//B[x; y] cand: 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


Home Index