mainline filter

The mainline filter consists of the single word mainline . It is true in a position if the position is a main line. It is not to be confused with the mainline keyword used in move filters.

variation filter

The variation filter consists of the single word variation . It is true in a position if the position is in a variation (of the whole game, not just of the previous move). It should not be confused with the variations keyword that is a CQL parameter.

Note that every position is either a mainline or a variation, but not both. Thus, the following compound filter is true in every position:

	  { 
	    mainline or variation
	    not {mainline variation}
	  }