title: Multiplying decimal and integer F#
body: <p>I'm learning f#.
  Considering this function:</p>
  
  <pre><code>let mult (a:decimal) (b:int) : decimal = a * b
  </code></pre>
  
  <p>When I try to compile I get this error:
  Error 1 Type constraint mismatch. The type int is not compatible with type decimal</p>
  
  <p>Why the compiler does not accept this?</p>
  
  <p>PS: When I explicity convert it does compile:</p>
  
  <pre><code>let mult (a:decimal) (b:int) : decimal = a * decimal(b)
  </code></pre>