[case].
'Command example:        CHECK|: case 2.'.
''.
'The "case" command tells the checker which case to consider.  When the'.
'"prove by cases" command is issued, the checker automatically begins on'.
'case 1; then, when the goal formula is proved using case 1, the checker'.
'automatically moves on to case 2, etc., until all cases have been proved.'.
'The user can override this sequence, moving back to an earlier case or'.
'forward to a later case, using the "case" command as above.'.
