Nuprl Lemma : length-zero-implies-nil

l:Base. [] supposing ||l|| 0 ∈ ℤ


Proof




Definitions occuring in Statement :  length: ||as|| nil: [] uimplies: supposing a all: x:A. B[x] natural_number: $n int: base: Base sqequal: t equal: t ∈ T
Definitions unfolded in proof :  all: x:A. B[x] uimplies: supposing a member: t ∈ T uall: [x:A]. B[x] nat: so_lambda: λ2x.t[x] so_apply: x[s] decidable: Dec(P) or: P ∨ Q satisfiable_int_formula: satisfiable_int_formula(fmla) exists: x:A. B[x] false: False implies:  Q not: ¬A top: Top and: P ∧ Q prop: sq_type: SQType(T) guard: {T} length: ||as|| list_ind: list_ind has-value: (a)↓ cons: [a b] label: ...$L... t ge: i ≥  nil: [] it:
Lemmas referenced :  bottom_diverge has-value-implies-dec-isaxiom-2 int_term_value_add_lemma itermAdd_wf nat_properties length-nat-if-has-value length_of_cons_lemma top_wf has-value-implies-dec-ispair-2 base_wf equal-wf-base int_formula_prop_wf int_formula_prop_eq_lemma int_term_value_var_lemma int_term_value_constant_lemma int_formula_prop_le_lemma int_formula_prop_not_lemma int_formula_prop_and_lemma intformeq_wf itermVar_wf itermConstant_wf intformle_wf intformnot_wf intformand_wf satisfiable-full-omega-tt decidable__le int-value-type le_wf set-value-type nat_wf value-type-has-value subtype_rel_self subtype_base_sq
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity lambdaFormation isect_memberFormation introduction cut thin instantiate lemma_by_obid sqequalHypSubstitution isectElimination because_Cache independent_isectElimination hypothesis sqequalRule lambdaEquality natural_numberEquality hypothesisEquality intEquality dependent_set_memberEquality equalityTransitivity equalitySymmetry dependent_functionElimination unionElimination dependent_pairFormation int_eqEquality isect_memberEquality voidElimination voidEquality independent_pairFormation computeAll independent_functionElimination sqequalAxiom baseApply closedConclusion baseClosed callbyvalueCallbyvalue callbyvalueReduce callbyvalueAdd productElimination applyEquality setElimination rename setEquality

Latex:
\mforall{}l:Base.  l  \msim{}  []  supposing  ||l||  =  0



Date html generated: 2016_05_14-AM-07_42_11
Last ObjectModification: 2016_01_15-AM-08_35_36

Theory : list_1


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