Nuprl Lemma : list-if-has-value-length

l:Base. l ∈ Base List supposing (||l||)↓


Proof




Definitions occuring in Statement :  length: ||as|| list: List has-value: (a)↓ uimplies: supposing a all: x:A. B[x] member: t ∈ T base: Base
Definitions unfolded in proof :  all: x:A. B[x] uimplies: supposing a member: t ∈ T length: ||as|| list_ind: list_ind uall: [x:A]. B[x] nat: implies:  Q false: False ge: i ≥  guard: {T} prop: subtype_rel: A ⊆B top: Top not: ¬A decidable: Dec(P) or: P ∨ Q iff: ⇐⇒ Q and: P ∧ Q rev_implies:  Q uiff: uiff(P;Q) subtract: m le: A ≤ B less_than': less_than'(a;b) true: True nat_plus: + has-value: (a)↓ cons: [a b] it: nil: []
Lemmas referenced :  nil_wf has-value-implies-dec-isaxiom-2 cons_wf int-value-type value-type-has-value top_wf has-value-implies-dec-ispair-2 fun_exp_unroll_1 le-add-cancel add-zero add_functionality_wrt_le add-commutes add-swap add-associates minus-minus minus-add minus-one-mul-top zero-add minus-one-mul condition-implies-le less-iff-le not-ge-2 false_wf subtract_wf decidable__le bottom_diverge strictness-apply fun_exp0_lemma base_wf int_subtype_base has-value_wf_base less_than_wf ge_wf less_than_irreflexivity less_than_transitivity1 nat_properties
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity lambdaFormation isect_memberFormation introduction cut sqequalHypSubstitution sqequalRule hypothesis compactness thin lemma_by_obid isectElimination hypothesisEquality setElimination rename intWeakElimination natural_numberEquality independent_isectElimination independent_functionElimination voidElimination lambdaEquality dependent_functionElimination axiomEquality equalityTransitivity equalitySymmetry baseApply closedConclusion baseClosed applyEquality isect_memberEquality voidEquality unionElimination independent_pairFormation productElimination addEquality intEquality minusEquality because_Cache dependent_set_memberEquality callbyvalueCallbyvalue callbyvalueReduce callbyvalueAdd

Latex:
\mforall{}l:Base.  l  \mmember{}  Base  List  supposing  (||l||)\mdownarrow{}



Date html generated: 2016_05_14-AM-06_33_19
Last ObjectModification: 2016_01_14-PM-08_24_07

Theory : list_0


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