This is documentation for Mathematica 6, which was
based on an earlier version of the Wolfram Language.

# Piecewise

 Piecewise[{{val1, cond1}, {val2, cond2}, ...}]represents a piecewise function with values vali in the regions defined by the conditions condi. Piecewise[{{val1, cond1}, ...}, val]uses default value val if none of the condi apply. The default for val is 0.
• The condi are typically inequalities such as .
• The condi are evaluated in turn, until one of them is found to yield True.
• If all preceding condi yield False, then the vali corresponding to the first condi that yields True is returned as the value of the piecewise function.
• If any of the preceding condi do not literally yield False, the Piecewise function is returned in symbolic form.
• Only those vali explicitly included in the returned form are evaluated.
• Elements of the form {vali, False} are dropped, as are all elements after the first {vali, True}.
• Piecewise[{{v1, c1}, {v2, c2}, ...}] can be input in the form . The piecewise operator can be entered as Esc pw Esc or \[Piecewise]. The grid of values and conditions can be constructed by first entering Ctrl+Comma, then using Ctrl+Enter and Ctrl+Comma.
Set up a piecewise function with different pieces below and above zero:
 Out[1]=

Find the derivative of a piecewise function:
 Out[1]=

Use Esc pw Esc to enter and Control+Comma and then