diff --git a/syntax.txt b/syntax.txt
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+++ b/syntax.txt
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+identifier:
+	identifier-start
+	identifier identifier-continue
+
+identifier-start:
+	nondigit
+
+identifier-contine:
+	digit
+	nondigit
+
+primary-expression:
+	identifier
+	constant
+	"(" expression ")"
+
+postfix-expression:
+	primary-expression
+	postfix-expression "[" expression "]"
+	postfix-expression "(" argument-expression-list? ")"
+	postfix-expression "<" for-expression ">"
+	postfix-expression "." identifier
+
+for-expression:
+	primary-expression
+	primary-expression "FOR" primary-expression
+
+argument-expression-list:
+	assignment-expression
+	argument-expression-list "," assignment-expression
+
+unary-expression:
+	postfix-expression
+	"NOT" unary-expression
+	"INT" unary-expression
+	"~" unary-expression	 # bitwise complement
+	"-" unary-expression	 # integer negation
+	"|" unary-expression "|" # integer absolute value
+
+multiplicative-expression:
+	unary-expression
+	multiplicative-expression "×" unary-expression
+	multiplicative-expression "/" unary-expression
+
+additive-expression:
+	multiplicative-expression
+	additive-expression "+" multiplicative-expression
+	additive-expression "-" multiplicative-expression
+
+shift-expression:
+	additive-expression
+	shift-expression "<<" additive-expression
+	shift-expression ">>" additive-expression
+
+relational-expression:
+	shift-expression
+	relational-expression "<" shift-expression
+	relational-expression ">" shift-expression
+	relational-expression "≤" shift-expression
+	relational-expression "≥" shift-expression
+
+equality-expression:
+	relational-expression
+	equality-expression "=" relational-expression
+	equality-expression "≠" relational-expression
+
+bitwise-AND-expression:
+	equality-expression
+	bitwise-AND-expression "∧" equality-expression
+
+bitwise-XOR-expression:
+	bitwise-AND-expression
+	bitwise-XOR-expression "⊕" bitwise-AND-expression
+
+bitwise-OR-expression:
+	bitwise-XOR-expression
+	bitwise-OR-expression "∨" bitwise-XOR-expression
+
+logical-AND-expression:
+	bitwise-OR-expression
+	logical-AND-expression "AND" bitwise-OR-expression
+
+logical-XOR-expression:
+	logical-AND-expression
+	logical-XOR-expression "XOR" logical-AND-expression
+
+logical-OR-expression:
+	logical-XOR-expression
+	logical-OR-expression "OR" logical-XOR-expression
+
+assignment-expression:
+	logical-OR-expression
+	unary-expression "←" assignment-expression
+
+expression:
+	assignment-expression
+
+# statement
+
+statement:
+	unlabeled-statement
+
+unlabeled-statement:
+	expression-statement
+	primary-block
+
+primary-block:
+	compound-statement
+	selection-statement
+	throw-statement
+
+secondary-block:
+	statement
+
+compound-statement:
+	"{" block-item-list? "}"
+
+block-item-list:
+	block-item
+	block-item-list block-item
+
+block-item:
+	unlabeled-statement
+
+expression-statement:
+	expression ";"
+
+selection-statement:
+	"IF" "(" expression ")" secondary-block
+	"IF" "(" expression ")" secondary-block "ELSE" secondary-block
+
+throw-statement:
+	"THROW" secondary-block