[ccp4bb] Refmac 5.6 and Twin operator

[Kiran Kulkarni]

Hi All,
 Is it possible to define twin operator and twin fraction in the latest version 
of Refmac (i.e., in version 5.6.0117) ?
I tried to define these two keywords in Buccaneer but it fails with an error 
message "Refmac_5.6.0117:  Problem in some of the instructions".
Please help me to fix this.
Many thanks,
-Kiran