Documentation for floating point function for S5

Dear expert,

I am doing a migration from S5 to Tia Portal

I would like to see the documentation for the floating point arithmetic package 6ES5 845-7GP01

FB15       GP:FPGP
FB16       GP:GPFP 
FB17       GP:ADD 
FB18       GP:SUB 
FB19       GP:MUL 
FB20       GP:DIVAM      
FB21       GP:VGL

​A description of the parameters of theses functions would help.

​