anchor.diff:        td m s#[sup &minus;1]
       tr
         td #[var W], #[var w]
  -      td Work done by the system / control volume
  +      td Work done by the fluid
         td J
       tr
         td: var &gamma;
  
positive.code:       td Energy head
        td m
      tr
        td: var m
        td Mass
        td kg
  
negative.code:       td Pa (N m#[sup &minus;2])
      tr
        td #[var Q], #[var q]
        td Heat flow into fluid
        td J
      tr
        td: var R
  