anchor.diff:        if ai.MoveNext() then
           if ai.Current = ei.Current then ()
           else
  -          Tests.failtestf "%s. String do not match at position %i. Expected: '%A', but got '%A'."
  +          Tests.failtestf "%s. String does not match at position %i. Expected: '%A', but got '%A'."
                               format i (ei.Current) (ai.Current)
         else
           Tests.failtestf "%s. String actual shorter than expected, at pos %i for expected '%A'."
  
positive.code:     if si.MoveNext() then
        if si.Current = pi.Current then ()
        else
          Tests.failtestf "%s. Sequence do not match at position %i. Expected: %A, but got %A."
                             format i (pi.Current) (si.Current)
      else
        Tests.failtestf "%s. Sequence actual shorter than expected, at pos %i for expected item %A."
  
negative.code:     if ai.MoveNext() then
        if ai.Current = ei.Current then ()
        else
          Tests.failtestf "%s. Sequence does not match at position %i. Expected: %A, but got %A."
                             format i (ei.Current) (ai.Current)
      else
        Tests.failtestf "%s. Sequence actual shorter than expected, at pos %i for expected item %A."
  