.ENABLE SUBSTITUTION
.LOOP:
.ASKS TSK TASK
.IFINS 'TSK' ; 'TSK' is installed
.IFINS ...'TSK' ; ...'TSK' is installed
.IFINS 'TSK' .AND .IFACT 'TSK' ; 'TSK' is active
.IFINS ...'TSK' .AND .IFACT ...'TSK' ; ...'TSK' is active
.GOTO LOOP