Where the edition cannot hold as stated, version by version: a
placement or pairing reference absent from the version, a command
placed relative to itself or in several ways at once, one claimed by
several pairs, a pair whose members are both placed and so cannot
keep their distance and follow their references at once, an
expression the version's own bar cannot read, a carrier sitting on a
track that does not say what its symbol says, and a strike that takes
nothing out.
Where the edition cannot hold as stated, version by version: a placement or pairing reference absent from the version, a command placed relative to itself or in several ways at once, one claimed by several pairs, a pair whose members are both placed and so cannot keep their distance and follow their references at once, an expression the version's own bar cannot read, a carrier sitting on a track that does not say what its symbol says, and a strike that takes nothing out.