They wouldn't like to, but they are ideologically close to SYRIZA as a Socialist party and would not have much of a choice, if there was a pure left wing majority. If they blocked a SYRIZA government they would be destroyed in the next election.
ANEL on the other hand is a right wing protest party, that would never join or support any government, especially not one with a Socialist party as the leading force.
This is definitely wrong on ANEL (and on DIMAR, to some extent). At the last election, ANEL and DIMAR all but campaigned on a coalition with SYRIZA. Neither would be unhappy about working with SYRIZA, though of course ANEL would rather their anti-austerity coalition partner were on the right (and probably prefers XA to SYRIZA as an ally). DIMAR would rather lead the coalition, but they wouldn't object to joining up with SYRIZA. (I'm somewhat surprised that they're even surviving--they were initially the anti-austerity center-left splinter, so joining a pro-austerity coalition should have killed them.)
