SQLAnywhere: Switch to choose between WATCOM and T-SQL? Is there any switch available to set/force a script using either Watcom or T-SQL dialect on SQLAnywehre?
No, but if you use a specific WSQL syntax (such as the SET statement), your procedure will be compiled as WSQL.  Similarly, if you use TSQL specific syntax (such as GOTO), your procedure will be compiled as TSQL.  Mixing the two syntaxes generally results in an error.