anchor.diff:      <@ addNeg @> ; 
       <@ multDivide1 @>; 
       <@ multDivide2 @>; 
  +    <@ negZero @>;
  +    <@ invOne @>
  +    <@ invInv @>
     ]
   
   let algebraicSimplificationRules = 
  
positive.code:     <@ assocSubSub1 @>; <@ assocSubSub2 @>; 
      <@ assocSubAdd1 @>; <@ assocSubAdd2 @>;
      <@ assocMultDiv1 @>; <@ assocMultDiv2 @>; 
      <@ assocDivMult @>;
      <@ comAdd @>; <@ comMult @>;
    ]
  
  
negative.code: let assocSubSub2       = <@ (%a - %b) - %c                <==>   (%a - %c) - %b      @>
  let assocSubAdd1       = <@ (%a - %b) + %c                <==>   (%a + %c) - %b      @>
  let assocSubAdd2       = <@ (%a - %b) + %c                <==>   %a + (%c - %b)      @>
  let assocMultMult      = <@ (%a * %b) * %c                <==>   %a * (%b * %c)      @>
  let assocMultDiv1      = <@ %a * (%b / %c)                <==>   (%a * %b) / %c      @>
  let assocMultDiv2      = <@ (%a * %b) / %c                <==>   %a * (%b / %c)      @>
  let assocDivMult       = <@ %a / (%b * %c)                <==>   (%a / %c) / %b      @>
  let comAdd             = <@ %a + %b                       <==>   %b + %a             @>
  let comMult            = <@ %a * %b                       <==>   %b * %a             @>
  let negZero            = <@ - (0.0)                       <==>   0.0                 @>
  let invOne             = <@ 1.0 / 1.0                     <==>   1.0                 @>
  // new basic axioms
  let subAddNeg          = <@ %a - %b                       <==>   %a + (- %b)         @>
  let divMult            = <@ %a / %b                       <==>   %a * (1.0 / %b)     @>
  let invInv             = <@ 1.0 / (1.0 / %a)              <==>   %a                  @>
  let invMult            = <@ 1.0 / (%a * %b)               <==>   (1.0/ %b)*(1.0/ %a) @>
  let comAddIndex        = <@ %i + %j                       <==>   %j + %i             @>
  let assocAddSubIndex   = <@ (%i + %j) - %k                <==>   %i + (%j - %k)      @>
  let assocSubAddIndex   = <@ (%i - %j) + %k                <==>   %i - (%j - %k)      @>
  