brace; in this case the newline will be included in the argument field along with any other characters up to the matching right brace. In many cases an argument field to one command consists of a Tcl command string that will be executed later; braces allow complex command structures to be built up without confusion. For example, the <CODE>
eval</CODE>
 command takes one argument, which is a command string; <CODE>
eval</CODE>
 invokes the Tcl interpreter to execute the command string. The command:</P>
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