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An expression is by itself a valid command. The effect of this
command is that the expression is evaluated in the current ring and
its value is displayed.
The evaluation of an expression in CoCoA is normally performed in a
full recursive evaluation mode.
Usually the result is the fully evaluated expression.
The result of the evaluation is automatically stored in the variable
It
.
/**/ 2 + 2;
4
/**/ It + 3;
7
/**/ It;
7
/**/ X := 5;
/**/ It;
7
|
The command
X := 5
is an assignment, not an evaluation; so it does
not change the value of the variable
It
.
If an error occurs during the evaluation of an expression, then the
evaluation is interrupted and the user is notified about the error.