<A NAME=WS>
<TITLE>WS</TITLE></A>
<b><a href=r37_idx.html>INDEX</a></b><p><p>
<B>WS</B> _ _ _ _ _ _ _ _ _ _ _ _ <B>operator</B><P>
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The <em>ws</em> operator alone returns the last result; <em>ws</em> with a
number argument returns the results of the REDUCE statement executed after
that numbered prompt.
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syntax: </H3>
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<em>ws</em>or <em>ws</em>(<number>)
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<number> must be an integer between 1 and the current REDUCE prompt number
.
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examples: </H3>
<P><PRE><TT></TT></PRE><P>(In the following examples, unlike most others, the nu
mbered
prompt is shown.)<P><PRE><TT>
1: df(sin y,y);
COS(Y)
2: ws^2;
2
COS(Y)
3: df(ws 1,y);
-SIN(Y)
</TT></PRE><P>
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<em>ws</em>and <em>ws</em><em>(</em><number><em>)</em> can be used anywher
e the
expression they stand for can be used. Calling a number for which no
result was produced, such as a switch setting, will give an error message.
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The current workspace always contains the results of the last REDUCE
command that produced an expression, even if several input statements
that do not produce expressions have intervened. For example, if you do
a differentiation, producing a result expression, then change several
switches, the operator <em>ws;</em> returns the results of the differentiation.
The current workspace (<em>ws</em>) can also be used inside files, though the
numbered workspace contains only the <em>in</em> command that input the file.
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There are three history lists kept in your REDUCE session. The first
stores raw input, suitable for the statement editor. The second stores
parsed input, ready to execute and accessible by
<A HREF=r37_0232.html>input</A>. The
third stores results, when they are produced by statements, which are
accessible by the <em>ws</em>< n> operator. If your session is very
long, storage space begins to fill up with these expressions, so it is a
good idea to end the session once in a while, saving needed expressions to
files with the
<A HREF=r37_0133.html>saveas</A> and
<A HREF=r37_0233.html>out</A> commands.
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An error message is given if a reference number has not yet been used.
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