Successive shortest paths: Difference between revisions

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'''Invariant:'''
'''Invariant:'''
The capacity constraints are fulfilled.
# The capacity constraints are fulfilled, that is, <math>0\leq f(a)\leq u(a)</math> for all <math>a\in A</math>.
# The '''balance discrepancy''' of each node <math>v\in V</math> is '''underestimating''', that is,


'''Variant:'''
'''Variant:'''
The '''balance discrepancy''' strictly decreases, that is, the value
The '''balance discrepancy''' strictly decreases, that is, the value
:<math>\sum_{v\in V}\left|\sum_{w:(v,w)\in A}f(v,w)-\sum_{w:(w,v)\in A}f(w,v)-b(v)\right|</math>.
:<math>\sum_{v\in V}\left|\sum_{w:(v,w)\in A}f(v,w)-\sum_{w:(w,v)\in A}f(w,v)-b(v)\right|</math>.
'''Induction basis:'''
'''Abstract view:'''
Start with an arbitrary value <math>f(a)\in[0\ldots u(a)

Revision as of 08:02, 23 October 2014

Abstract view

Invariant:

  1. The capacity constraints are fulfilled, that is, [math]\displaystyle{ 0\leq f(a)\leq u(a) }[/math] for all [math]\displaystyle{ a\in A }[/math].
  2. The balance discrepancy of each node [math]\displaystyle{ v\in V }[/math] is underestimating, that is,

Variant: The balance discrepancy strictly decreases, that is, the value

[math]\displaystyle{ \sum_{v\in V}\left|\sum_{w:(v,w)\in A}f(v,w)-\sum_{w:(w,v)\in A}f(w,v)-b(v)\right| }[/math].

Induction basis:

Abstract view: Start with an arbitrary value <math>f(a)\in[0\ldots u(a)