Nuprl Lemma : FormOr_wf2

[C:Type]. ∀[a,b:PZF-Formula(C)].  (a ∨ b ∈ PZF-Formula(C))


Proof




Definitions occuring in Statement :  PZF-Formula: PZF-Formula(C) FormOr: left ∨ right uall: [x:A]. B[x] member: t ∈ T universe: Type
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T PZF-Formula: PZF-Formula(C) PZF-Form: PZF-Form(C) and: P ∧ Q cand: c∧ B prop: not: ¬A implies:  Q false: False assert: b ifthenelse: if then else fi  termForm: termForm(f) Form_ind: Form_ind FormOr: left ∨ right bfalse: ff wfForm: wfForm(f) wfFormAux: wfFormAux(f) bnot: ¬bb band: p ∧b q btrue: tt uiff: uiff(P;Q) rev_uimplies: rev_uimplies(P;Q) uimplies: supposing a squash: T iff: ⇐⇒ Q rev_implies:  Q true: True SafeForm: SafeForm(f)
Lemmas referenced :  FormOr_wf assert_wf wfForm_wf SafeForm_wf termForm_wf not_wf PZF-Formula_wf assert_of_band wfFormAux_wf bfalse_wf squash_wf true_wf bool_wf iff_imp_equal_bool false_wf
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation introduction cut sqequalHypSubstitution setElimination thin rename dependent_set_memberEquality productElimination extract_by_obid isectElimination cumulativity hypothesisEquality hypothesis independent_pairFormation productEquality lambdaFormation sqequalRule axiomEquality equalityTransitivity equalitySymmetry isect_memberEquality because_Cache universeEquality applyEquality independent_isectElimination hyp_replacement lambdaEquality imageElimination voidElimination independent_functionElimination natural_numberEquality imageMemberEquality baseClosed

Latex:
\mforall{}[C:Type].  \mforall{}[a,b:PZF-Formula(C)].    (a  \mvee{}  b  \mmember{}  PZF-Formula(C))



Date html generated: 2018_05_21-PM-11_38_15
Last ObjectModification: 2017_10_12-PM-05_14_26

Theory : PZF


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