diff --git a/nessesary/parser/structure.py b/nessesary/parser/structure.py
new file mode 100644
index 0000000..8040514
--- /dev/null
+++ b/nessesary/parser/structure.py
@@ -0,0 +1,91 @@
+#VARIABLE AND NUMBER
+VAR = 0
+NUM = 1
+POINT = 2
+
+# OPERATOR
+PLUS_S = 3
+MINUS_S = 4
+MUL_S = 5
+DIV_S = 6
+EXP_S = 7
+
+# BRACKET AND PARENTHESES
+LEFT_BRAC = 11
+RIGHT_BRAC = 12
+LEFT_PAR = 10
+RIGHT_PAR = 11
+
+#FUNCTION
+SQRT_FUNC = 100
+SIN_FUNC = 101
+COS_FUNC = 102
+TAN_FUNC = 103
+SEC_FUNC = 104
+COSEC_FUNC = 105
+COT_FUNC = 106
+ASIN_FUNC = 107
+ACOS_FUNC = 108
+ATAN_FUNC = 109
+ASEC_FUNC = 110
+ACOSEC_FUNC = 111
+ACOT_FUNC = 112
+FACTORIAL = 113
+LOG = 114
+LN = 115
+
+ALPHABET_LIST = ['a', 'b', 'c', 'd', 'e', 'f', 
+                    'g', 'h', 'i', 'j', 'k', 'l',
+                    'm', 'n', 'o', 'p', 'q', 'r', 's'
+                    , 't', 'u', 'v', 'w', 'x', 'y', 'z']
+
+NUM_LIST = ['1','2','3','4','5','6','7','8','9','0']
+
+def general_parse(expr):
+
+    result_list = []
+    for value in expr:
+        if value == "+":
+            result_list.append(PLUS_S)
+        elif value == "-":
+            result_list.append(MINUS_S)
+        elif value == "*":
+            result_list.append(MUL_S)
+        elif value == "/":
+            result_list.append(DIV_S)
+        elif (value == "^") or (value == "*"):
+            result_list.append(EXP_S)
+        elif value == ".":
+            result_list.append(POINT)
+
+        elif value == "(":
+            result_list.append(LEFT_PAR)
+        elif value == ")":
+            result_list.append(RIGHT_PAR)
+        elif value == "[":
+            result_list.append(LEFT_BRAC)
+        elif value == "]":
+            result_list.append(RIGHT_BRAC)
+
+        elif value in ALPHABET_LIST:
+            result_list.append(VAR)
+        elif value in NUM_LIST:
+            result_list.append(NUM)
+
+    """
+    MEANING OF EACH PATTERN EXPRESSION.
+        RESULT_LIST     MEANING
+        [1,1,1,...]       1231..
+        [0,0,0]            xyz
+        [1,1,2,1,1]       12.32
+        [1,1,0]            15x
+        [10,11]            ()
+        [12,13]            []
+        [114,10,,11]      log()
+        [115,10,,11]       ln()
+        [1,1,113]          31!
+        [101,10,,11]      sin()
+    [1,0,3,10,1,2,1,
+  101,10,1,1,1,11,11]   5x+(4.2sin(324))
+     """
+