Nuprl Lemma : vars-of-subst-not-nullvar

[opr:Type]. ∀[s:(varname() × term(opr)) List].  (nullvar() ∈ vars-of-subst(s)))


Proof




Definitions occuring in Statement :  vars-of-subst: vars-of-subst(s) term: term(opr) nullvar: nullvar() varname: varname() l_member: (x ∈ l) list: List uall: [x:A]. B[x] not: ¬A product: x:A × B[x] universe: Type
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T not: ¬A implies:  Q false: False all: x:A. B[x] l_member: (x ∈ l) exists: x:A. B[x] cand: c∧ B prop: nat: uimplies: supposing a ge: i ≥  decidable: Dec(P) or: P ∨ Q satisfiable_int_formula: satisfiable_int_formula(fmla) and: P ∧ Q subtype_rel: A ⊆B
Lemmas referenced :  vars-of-subst_wf select_wf varname_wf not_wf equal_wf nullvar_wf nat_properties decidable__le full-omega-unsat intformand_wf intformnot_wf intformle_wf itermConstant_wf itermVar_wf istype-int int_formula_prop_and_lemma int_formula_prop_not_lemma int_formula_prop_le_lemma int_term_value_constant_lemma int_term_value_var_lemma int_formula_prop_wf l_member_wf subtype_rel_list equal-wf-T-base istype-void list_wf term_wf istype-universe
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation_alt introduction cut lambdaFormation_alt thin extract_by_obid sqequalHypSubstitution isectElimination hypothesisEquality hypothesis inhabitedIsType productElimination closedConclusion setEquality setElimination rename because_Cache independent_isectElimination dependent_functionElimination natural_numberEquality unionElimination approximateComputation independent_functionElimination dependent_pairFormation_alt lambdaEquality_alt int_eqEquality Error :memTop,  sqequalRule independent_pairFormation universeIsType voidElimination equalitySymmetry equalityIstype equalityTransitivity applyEquality baseClosed setIsType functionIsType functionIsTypeImplies productEquality isect_memberEquality_alt isectIsTypeImplies instantiate universeEquality

Latex:
\mforall{}[opr:Type].  \mforall{}[s:(varname()  \mtimes{}  term(opr))  List].    (\mneg{}(nullvar()  \mmember{}  vars-of-subst(s)))



Date html generated: 2020_05_19-PM-09_57_44
Last ObjectModification: 2020_03_09-PM-04_09_58

Theory : terms


Home Index