log_exp - ( )

Syntax

... ( log_exp ) ...

Effect

A complete logical expression log_exp can be put in round brackets. log_exp can be a link of multiple expressions with AND or OR or a logical expression which was negated with NOT. A bracketed logical expression constitutes again a logical expression.

Example

Linking of logical expressions

NOT log_exp1 OR log_exp2 AND NOT log_exp3 AND log_exp4

Can be bracketed explicitly as follows to clarify the implicit bracketing:

1. Bracketing the expressions with NOT
   ( NOT log_exp1 ) OR
   log_exp2 AND ( NOT log_exp3 ) AND log_exp4 ...
   
   
2. Bracketing the expressions with AND
   ( NOT log_exp1 ) OR
   ( log_exp2 AND ( NOT log_exp3 ) AND log_exp4 ) ...
   
   
3. Bracketing the expressions with OR
   ( ( NOT log_exp1 ) OR
   ( log_exp2 AND ( NOT log_exp3 ) AND log_exp4 ) ) ...

A different explicit bracketing changes the meaning of the expression. If you set explicit brackets as follows in the above expression:

( NOT log_exp1 OR log_exp2 ) AND
NOT ( log_exp3 AND log_exp4 )

the result after implicit bracketing is:

( ( ( NOT log_exp1 ) OR log_exp2 ) AND
  ( NOT ( log_exp3 AND log_exp4 ) ) )