Using white-knight based establishment

White knights require
- an establisher
- for every deleter, a white-knight that re-establishes

Don’t need to consider the threats to every causal link separately
- O(k2*|U|) causal link variables eliminated

O(k*(|O|+|U|))variables

Some preceding step adds

Estab(S1,Pj,Si) => Adds(S1, Pj)

& Precedes (S1, Sj)

For every preceding step deleting a needed condition,

there is a white-knight that adds it back

Needs(Sj, Pj) & Deletes(Sd, Pj) & Precedes(Sd,Sj)

=> Wknight(S1, Sj, Sd, Pj) V

Wknight(S2,Sj,Sd,Pj) V ….

Wknight(Sw,Sj,Sd,Pj) => Precedes(Sw, Sj) &

Precedes(Sd, Sw) & Adds(Sw, Pj)