Hello,

How to solve this error? Thank you

Sistem := diff(E[1](t), t) = subs(E[1] = E[1](t), L[1] = L[1](t), P[1] = P[1](t), M[1] = M[1](t), E[2] = E[2](t), L[2] = L[2](t), P[2] = P[2](t), M[2] = M[2](t), Data, dE1), diff(L[1](t), t) = subs(E[1] = E[1](t), L[1] = L[1](t), P[1] = P[1](t), M[1] = M[1](t), E[2] = E[2](t), L[2] = L[2](t), P[2] = P[2](t), M[2] = M[2](t), Data, dL1), diff(P[1](t), t) = subs(E[1] = E[1](t), L[1] = L[1](t), P[1] = P[1](t), M[1] = M[1](t), E[2] = E[2](t), L[2] = L[2](t), P[2] = P[2](t), M[2] = M[2](t), Data, dP1), diff(M[1](t), t) = subs(E[1] = E[1](t), L[1] = L[1](t), P[1] = P[1](t), M[1] = M[1](t), E[2] = E[2](t), L[2] = L[2](t), P[2] = P[2](t), M[2] = M[2](t), Data, dM1), diff(E[2](t), t) = subs(E[1] = E[1](t), L[1] = L[1](t), P[1] = P[1](t), M[1] = M[1](t), E[2] = E[2](t), L[2] = L[2](t), P[2] = P[2](t), M[2] = M[2](t), Data, dE2), diff(L[2](t), t) = subs(E[1] = E[1](t), L[1] = L[1](t), P[1] = P[1](t), M[1] = M[1](t), E[2] = E[2](t), L[2] = L[2](t), P[2] = P[2](t), M[2] = M[2](t), Data, dL2), diff(P[2](t), t) = subs(E[1] = E[1](t), L[1] = L[1](t), P[1] = P[1](t), M[1] = M[1](t), E[2] = E[2](t), L[2] = L[2](t), P[2] = P[2](t), M[2] = M[2](t), Data, dP2), diff(M[2](t), t) = subs(E[1] = E[1](t), L[1] = L[1](t), P[1] = P[1](t), M[1] = M[1](t), E[2] = E[2](t), L[2] = L[2](t), P[2] = P[2](t), M[2] = M[2](t), Data, dM2);
Error, invalid input: subs received Data, which is not valid for its 9-th argument