Nuprl Lemma : iff_transitivity

∀[P,Q,R:ℙ].  ((P ⇐⇒ Q) ⇒ (Q ⇐⇒ R) ⇒ (P ⇐⇒ R))


Proof




Definitions occuring in Statement :  uall: ∀[x:A]. B[x],  prop: ℙ,  iff: P ⇐⇒ Q,  implies: P ⇒ Q
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  implies: P ⇒ Q,  iff: P ⇐⇒ Q,  and: P ∧ Q,  member: t ∈ T,  prop: ℙ,  rev_implies: P ⇐ Q
Lemmas referenced :  iff_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  Error :isect_memberFormation_alt,  lambdaFormation,  sqequalHypSubstitution,  productElimination,  thin,  independent_pairFormation,  independent_functionElimination,  hypothesis,  hypothesisEquality,  cut,  introduction,  extract_by_obid,  isectElimination,  Error :inhabitedIsType,  Error :universeIsType,  universeEquality

Latex:
\mforall{}[P,Q,R:\mBbbP{}].    ((P  \mLeftarrow{}{}\mRightarrow{}  Q)  {}\mRightarrow{}  (Q  \mLeftarrow{}{}\mRightarrow{}  R)  {}\mRightarrow{}  (P  \mLeftarrow{}{}\mRightarrow{}  R))



Date html generated: 2019_06_20-AM-11_16_41
Last ObjectModification: 2018_09_26-AM-10_24_20

Theory : core_2


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