kill(all);

topolino : pippo;

pippo : clarabella ^2 ;

ev ( topolino , clarabella=0);

ev ( topolino , clarabella=0);

implicit evaluation, called by the "SHIFT-ENTER" keypress

ev ( pippo    , clarabella=0);

explicit evaluation, called by the ev( ) function

clarabella^2

ev( clarabella^2 , clarabella=0 )

0

ev(
    ev(
        ev ( topolino , clarabella=0), clarabella=0
    ),clarabella=0
);

infeval: repeat the evaluation under the given hypotheses
until two subsequent evaluations return the same expression

ev( topolino, clarabella=0, infeval);

eval: repeat the evaluation one time more

ev( topolino, clarabella=0, eval);

ev( topolino, clarabella=0, eval,eval);

ev( topolino, clarabella=0, eval,eval,eval);