- expr1 and expr2 represent expressions

- The operator != evaluates to true iff its operands expr1 and
expr2 are syntactically unequal and both different from error or
constant expressions that are not constants and that evaluate to two
different floating-point number with the global precision prec. The
user should be aware of the fact that because of floating-point
evaluation, the operator != is not exactly the same as the
negation of the mathematical equality.

Note that the expressions !(expr1 != expr2) and expr1 == expr2 do not evaluate to the same boolean value. See error for details.

false

> "Hello" != "Salut";

true

> "Hello" != 5;

true

> 5 + x != 5 + x;

false

false

> asin(1) * 2 != pi;

false

> exp(5) != log(4);

true

true

The precision has been set to 12 bits.

> 16384.1 != 16385.1;

false

false