The keyword var allows for the declaration of local variables
identifier1 through identifiern in a begin-end-block ({}-block).
Once declared as a local variable, an identifier will shadow
identifiers declared in higher scopes and undeclared identifiers
available at top-level.
Variable declarations using var are only possible in the
beginning of a begin-end-block. Several var statements can be
given. Once another statement is given in a begin-end-block, no more
var statements can be given.
Variables declared by var statements are dereferenced as error
until they are assigned a value.
Example 1:
> exp(x);
exp(x)
> a = 3;
> {var a, b; a=5; b=3; {var a; var b; b = true; a = 1; a; b;}; a; b; };
1
true
5
3
> a;
3