/*
<Program> ::= <statement>

<lx_label> ::= @<name>
<identifier> ::= $<char>{<char>} 
<robot_commands> ::= ? [turn | auto | prod <expression> | 
						sell <expression>, <expression> | buy <expression>, <expression>
						print "<string>", <expression> {,<expression>}  ]

<statement> ::= 
	<identifier> [ '['<expression>']' ] := <expression> | 
	if (<expression>) <statement> [else <statement>] |
    goto <lx_label> | <lx_label> |
	'{' <statement> {;<statement>} '}' |
	<robot_commands>


<expression> ::= <and> {'&' <and>}

<and> ::= <or> {'|' <or>}
<or> ::= <bool> [ > |< |= ] <bool> ]
<bool> ::= <term> { [ +| - ] <term> }
<term> ::= <primary> {[ *| /| %] <primary>}

<name_data> ::= <char>{<char>}[ '['<expression>']' ]

<primary> ::= 
	<identifier> [ '['<expression>']' ] | 
	.<name_data>{.<name_data>} |
	<integer_const> | 
	(<expression>) |

	-<primary> | 
	!<primary>
*/