Linear ordering constraints are potentially very complicated between realisations of different slots, and can be conditional, in particular, on optional positions when these are involved in the frame. We suggest here a simple way to deal with ordering constraints. We decided not to give the possibility of expressing a conditional ordering relation: the apparent need for such constraints is rather a criterion to split into two different frames in our approach. Thus, two complicated conditional ordering relations should be solved by splitting into two (or more) frames.
We propose to give the possibility of describing ordering constraints only when linking one element of one frame (slots or slot realisations) to another one or to the verb (self), different linear ordering constraints attached to the same frame being independent of each other.