Ekran görüntüsü 2022-08-04 151824.png You do this via a mapping set: pf(p,f). You also need this for P_m: set m /m1*m3/, g /g1*g5/, p /p1*p5/, f /f1*f5/; set pf(p,f) / #p:#f /, mp(m,p) / m1.(p1,p2,p3), m2.(p2,p3,p4), m3.(p3,p4,p5) /; variable B(m,p,g), A(m,f,g); equation e(p,m,g); e(p,m,g)$mp(m,p)....