Sometimes in guitar pro I see notes with both the hammer on and sliding notation at the same time?

Does this mean I do both, or does it just mean you can do whichever one you want?
Do whatever sounds right for the song, If it is a slide you can surely tell because the pitch rises as opposed to being instantly shifted.
I'm pretty certain that's just a legato slide isn't it? (Meaning you slide without picking the note you arrive at)
I used to play the viola, the curved part underneath the notes is a slur, so you won't pick the second note (or change the direction of the bow for a violin/viola/cello). The slide just tells you how to get to the 2nd note. Actually, since its only one fret, the slide isnt that big a deal.
I see no hammer on there, just a quick slide down from an Ab to a G.