Editing Guarded Command Language (section)

===Semantics===
Execution of the repetition consists of executing 0 or more ''iterations'', where an iteration consists of arbitrarily choosing a guarded command {{math|Gi → Si}} whose guard {{math|Gi}} is true and executing the command {{math|Si}}. Thus, if all guards are initially false, the repetition terminates immediately, without executing an iteration. Execution of the repetition '''do od''', which has no guarded commands, executes 0 iterations, so '''do od''' is equivalent to '''skip'''.