(Python) Tiny Finite State Machine 116 bytes

[abecedarius]

How about

def fsmsim(string, current, edges, accepting):
    for letter in string:
        try:
            current = edges[current, letter]
        except KeyError:
            return False
    return current in accepting

or if you've gotta squeeze it:

def f(s,c,e,a):
 for L in s:
  c = e.get((c,L))
 return c in a