Nuprl Lemma : lg-acyclic-has-source

∀[T:Type]. ∀g:LabeledGraph(T). (∃i:ℕlg-size(g). (↑lg-is-source(g;i))) supposing (lg-acyclic(g) and 0 < lg-size(g))


Proof




Definitions occuring in Statement :  lg-is-source: lg-is-source(g;i),  lg-acyclic: lg-acyclic(g),  lg-size: lg-size(g),  labeled-graph: LabeledGraph(T),  int_seg: {i..j-},  assert: ↑b,  less_than: a < b,  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  natural_number: $n,  universe: Type
Lemmas :  int_seg_wf,  lg-size_wf,  exists_wf,  lg-edge_wf,  all_wf,  nat_wf,  equal_wf,  nat_plus_properties,  lg-connected_wf,  fun_exp_wf,  zero-le-nat,  le_wf,  false_wf,  lelt_wf,  primrec-wf-nat-plus,  nat_plus_wf,  lg-edge-lg-connected,  decidable__le,  not-le-2,  sq_stable__le,  condition-implies-le,  minus-add,  minus-one-mul,  zero-add,  add-associates,  add-swap,  add-commutes,  add_functionality_wrt_le,  add-zero,  le-add-cancel,  fun_exp_add1,  lg-connected_transitivity,  subtype_base_sq,  int_subtype_base,  pigeon-hole-implies,  less-iff-le,  decidable__lt,  add-mul-special,  zero-mul,  int_seg_subtype-nat,  sq_stable__equal,  subtract_wf,  less_than_transitivity2,  le_weakening2,  less_than_irreflexivity,  less_than_wf

Latex:
\mforall{}[T:Type]
    \mforall{}g:LabeledGraph(T)
        (\mexists{}i:\mBbbN{}lg-size(g).  (\muparrow{}lg-is-source(g;i)))  supposing  (lg-acyclic(g)  and  0  <  lg-size(g))



Date html generated: 2015_07_22-PM-00_29_35
Last ObjectModification: 2015_01_28-PM-11_35_18

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