Nuprl Lemma : dl-equiv_wf

[phi,psi:Prop].  ((phi ⇐⇒ psi) ∈ ℙ')


Proof




Definitions occuring in Statement :  dl-equiv: (phi ⇐⇒ psi) dl-prop: Prop uall: [x:A]. B[x] prop: member: t ∈ T
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T dl-equiv: (phi ⇐⇒ psi) prop: and: P ∧ Q
Lemmas referenced :  dl-valid_wf dl-implies_wf dl-prop_wf
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation_alt introduction cut sqequalRule productEquality extract_by_obid sqequalHypSubstitution isectElimination thin hypothesisEquality hypothesis axiomEquality equalityTransitivity equalitySymmetry inhabitedIsType isect_memberEquality_alt isectIsTypeImplies universeIsType

Latex:
\mforall{}[phi,psi:Prop].    ((phi  \mLeftarrow{}{}\mRightarrow{}  psi)  \mmember{}  \mBbbP{}')



Date html generated: 2019_10_15-AM-11_44_15
Last ObjectModification: 2019_03_27-AM-00_13_56

Theory : dynamic!logic


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