A.2.11 Special Input
| ?symbol | get information | | ??symbol | get more information | ?  ... | get information on several objects | | !command | execute an external command | | !!file | display the contents of an external file |
Special input lines. In most implementations of Mathematica, you can give a line of special input anywhere in your input. The only constraint is that the special input must start at the beginning of a line. Some implementations of Mathematica may not allow you to execute external commands using !command.
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