View Compilation Error

0_0_29311418_42.cpp: In function 'int main()':
0_0_29311418_42.cpp:72:82: error: lvalue required as left operand of assignment
         if (Check(a,b,c)==0 ||Check(a,b,d)==0 || Check(a, c ,d)==0 ||Check(b,c,d)=0) {
                                                                                  ^