span(List) -- construct smallest interval

• Function: span

• Usage:

  I = span(L)

  I = span(L,Precision => prec)

• Inputs:
  • L, a list, containing Number (including RRi)
• Optional inputs:
  • Precision => an integer, default value -1, specifies the desired precision of the output, a value of -1 uses the minimum precision of the inputs.
• Outputs:
  • I, a real interval,