Source : Free On-Line Dictionary of Computing

ABC ALGOL
     
         An extension of {ALGOL 60} with arbitrary data
        structures and user-defined operators, for {symbolic
        mathematics}.
     
        ["ABC ALGOL, A Portable Language for Formula Manipulation
        Systems", R.P. van de Riet, Amsterdam Math Centrum 1973].
     
        (1994-10-28)