title: Why can't I define this symbol in masm?
body: <p>I'm just starting to learn intel assembly and I'm having trouble with this simple program.</p>
  
  <pre><code>main    PROC            ;program execution begins here
  A   =   1               ;define A with 1
  B   =   12o             ;define B with 12 octal
  X   dword   A1h         ;initialize the variable X with value A1 hex
  Y   dword   11001001b   ;initialize the variable Y with value 11001001 binary
  
  SUM dword   0       ;initializes the sum variable to 0
  ADD EAX, A          ;adds A to sum
  ADD EAX, B          ;adds B to sum
  ADD EAX, X          ;adds X to sum
  ADD EAX, Y          ;adds Y to sum
  MOV SUM, EAX        ;
  exit                ;end of program
  main    ENDP
  </code></pre>
  
  <p>but whenever I try to build this it says "Error A2006: undefined symbol : A1"
  if anyone could help me that'd be great.</p>