The Unsolvability of the Equivalence Problem for epsilon-free NGSM's with Unary Input (Output) Alphabet and Applications

The Unsolvability of the Equivalence Problem for epsilon-free NGSM's with Unary Input (Output) Alphabet and Applications Oscar H. Ibarra 74-81 conf/focs/FOCS18 1977 FOCS db/conf/focs/focs77.html#Ibarra77