Nuprl Lemma : or_comm

∀[A,B:ℙ].  (A ∨ B ⇐⇒ B ∨ A)


Proof




Definitions occuring in Statement :  uall: ∀[x:A]. B[x],  prop: ℙ,  iff: P ⇐⇒ Q,  or: P ∨ Q
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  iff: P ⇐⇒ Q,  and: P ∧ Q,  implies: P ⇒ Q,  or: P ∨ Q,  guard: {T},  member: t ∈ T,  prop: ℙ,  rev_implies: P ⇐ Q
Lemmas referenced :  or_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  Error :isect_memberFormation_alt,  independent_pairFormation,  lambdaFormation,  sqequalHypSubstitution,  unionElimination,  thin,  sqequalRule,  cut,  hypothesis,  inrFormation,  hypothesisEquality,  inlFormation,  introduction,  extract_by_obid,  isectElimination,  because_Cache,  Error :inhabitedIsType,  Error :universeIsType,  universeEquality

Latex:
\mforall{}[A,B:\mBbbP{}].    (A  \mvee{}  B  \mLeftarrow{}{}\mRightarrow{}  B  \mvee{}  A)



Date html generated: 2019_06_20-AM-11_16_01
Last ObjectModification: 2018_09_26-AM-10_23_57

Theory : core_2


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