Conditional statement
The two forms of conditional statement are: 
	if expression
		statement
		
	if expression
		statement
	else
		statement
If/else statements can be written without the use of parentheses and curly brackets.  Multi-line conditionals are delimited by indentation. In both of the above cases, the expression is evaluated if it is non-zero, the first statement is executed. In the second case, the second statement is executed if the expression is evaluated 0. In the second case,  dangling else ambiguity is solved by appending if to else key word.


While statement
The While statement has the forms:
	while expression
		(body block)

	statement  while expression
In the first form, the code in body block will be executed repeatedly so long as the expression is boolean true.
In the second form, the statement will be executed repeatedly so long as expression is boolean true. The judgment is made every time before the execution of statement.


For statement
The For statement has the following form:
	statement for identifier in array (by integer)

	statement for identifier, identifier of object (by integer)
In the first form, for statement iterate through the array element by element, and use these element to execute in the first statement. In the second form, for statement uses two identifier to iterate through an object attribute by attribute, the first identifier will be the attribute name and the second identifier will be the attribute value. The two identifiers are both used in the previous statement.
Both of the forms can be append by (by integer), which indicate the chunk size of each step in iteration.


Block
LGA uses indentation to indicate a block of code as a whole
	statement
		(body of block)
	statement
A block in LGA always begin with an indent and ends with an outdent


Identifier 
To define a variable in LGA, use a legal name for an identifier, a sequence of and only of letters, digits an underscores other than key words of the language, and identifiers must begin with a letter. To define an identifier, use the following form:
	identifier =  expression
Expression will be evaluated and the result value of it will be set as the initial value of identifier.


Literal
A literal in LGA is the immediate value of constant or boolean expression. For integer or string constants, the literals of them are their own values. For comparing expressions, the literal of them are boolean true or false, according to the result of judgement. For others, literal is not applicable.


Assignment
LGA has two forms of assignment:
	assignable = expression

	assignable = 
		expression
In the first form, the result of evaluation the expression will be set as the value of assignable. In the second form, it act the same way and skip the indentation after =.
