Question: IF statement not working

Hi, I am currently creating a procedure so that i can input two matrices and a vector and multiply them together in different patterns, I want the result to be either one of the vectors {4,0,0,0} or {0,4,0,0} or {0,0,4,0} or {0,0,0,4}, I am trying to create an if loop that says is one of the S's is equal to one of these print ("Synchronising"), I have decalred these vectors inside the procedure and all the S's but my if statement is still not working. I think S needs to be decalred more clearly inside but i'm unsure what to do, any help would be much appreciaited! Here is my procedure:

proc_cerny1:=proc(A::Matrix,B::Matrix,C::Vector)
local s, s1, s2, s3, s4, s5, s6, s7, s8, s9, s10, s11, s12, s13, s14, e, f, g, h;
s:=C.A;
s1:=C.B;
s2:=C.A.B;
s3:=C.B.A;
s4:=C.A.A;
s5:=C.B.B;
s6:=C.A.A.A;
s7:=C.B.B.B;
s8:=C.A.B.B;
s9:=C.A.B.A;
s10:=C.B.B.A;
s11:=C.B.A.A;
s12:=C.A.A.B;
s12:=C.B.A.B;
s13:=C.B.A.A;
s14:=C.B.A.A.A;
e:=Vector([4,0,0,0],orientation=row);
f:=Vector([0,4,0,0],orientation=row);
g:=Vector([0,0,4,0],orientation=row);
h:=Vector([0,0,0,4],orientation=row);
g:=Vector([0,0,4,0],orientation=row);
if (s7 = e)then
print("Synchronising")
elif (s7 = g) then
print ("Synchronising")
elif (s7 = h) then
print ("Synchronising")
elif (s7 = g) then
print("Synchronising")
else
print("Not Synchronising");
end if;

return s, s1, s2, s3, s4, s5, s6, s7, s8, s9, s10, s11, s12, s13, s14;
end proc:

Thanks