;
exp10a : CASEXP exp OF '{' alts end {$$ = gc6(ap(CASE,pair($2,rev($5))));}
| DO '{' stmts end {$$ = gc4(ap(DOCOMP,checkDo($3)));}
;
exp10a : CASEXP exp OF '{' alts end {$$ = gc6(ap(CASE,pair($2,rev($5))));}
| DO '{' stmts end {$$ = gc4(ap(DOCOMP,checkDo($3)));}