Compilare: user.cpp: In function ‘void Back()’: user.cpp:13:7: warning: unused variable ‘i’ [-Wunused-variable] { int i,i1,i2,i3,i4 ; ^ user.cpp: In function ‘void Mult(double (*)[25], double (*)[25])’: user.cpp:39:35: warning: unused variable ‘l2’ [-Wunused-variable] { int i,j,t,l1=a[0][0],c1=a[0][1],l2=b[0][0],c2=b[0][1]; ^ user.cpp: In function ‘int main()’: user.cpp:56:30: warning: unused variable ‘p4’ [-Wunused-variable] { int i,j,t; double p1,p2,p3,p4; ^