This expression works fine : CORR#((ACH#(LN#(X(RI)~E),1M)),(ACH#(LN#(TAUGVG4(RI)~E),1M)),120M) but as you can see I need to declare one of the two variables (TAUGVG4 in this case). I would like to know if it is possible to create an expression with two symbols variables working in the API ? So a formula like this CORR#((ACH#(LN#(X(RI)~E),1M)),(ACH#(LN#(Y(RI)~E),1M)),120M) ?

Thanks in advance for your help.