diff --git a/doc/examples/use-case-1.txt b/doc/examples/use-case-1.txt
index c9d06d5..edf5d7a 100644
--- a/doc/examples/use-case-1.txt
+++ b/doc/examples/use-case-1.txt
@@ -5,8 +5,8 @@ function g = { x - 2: x < 3,
              };
 fun h = x/(x-2);
 
-evaluate f in 3;
+evaluate f in (3);
 g(5);
-evaluate g in 4;
+evaluate g in (4);
 g(2);
 h(2);
\ No newline at end of file
diff --git a/doc/examples/use-case-14.txt b/doc/examples/use-case-14.txt
index 1d7f40f..719932c 100644
--- a/doc/examples/use-case-14.txt
+++ b/doc/examples/use-case-14.txt
@@ -1,2 +1,2 @@
 fun f = 1/x;
-derivative f in 3 err -2;
\ No newline at end of file
+derivative f in (3) err -2;
\ No newline at end of file
diff --git a/doc/examples/use-case-5.txt b/doc/examples/use-case-5.txt
index 760dedb..d8578c3 100644
--- a/doc/examples/use-case-5.txt
+++ b/doc/examples/use-case-5.txt
@@ -1,6 +1,6 @@
 fun f = x^2;
-derivative f in 3;
-derivative 2 f in 3;
-derivative 3 f in 3;
-derivative 4 f in 3;
-derivative 5 f in 3;
\ No newline at end of file
+derivative f in (3);
+derivative 2 f in (3);
+derivative 3 f in (3);
+derivative 4 f in (3);
+derivative 5 f in (3);
\ No newline at end of file
diff --git a/doc/examples/use-case-7.txt b/doc/examples/use-case-7.txt
index 01f6d6e..fae0232 100644
--- a/doc/examples/use-case-7.txt
+++ b/doc/examples/use-case-7.txt
@@ -2,4 +2,4 @@ fun f = - x^2 / 2 + 5*x;
 fun g = x^2 - 5*x - 2;
 fun h = x^2 - 5*x - 82;
 
-integrate [f, g, h] between 2 ~ 7;
\ No newline at end of file
+integrate [f, g, h] between (2 ~ 7);
\ No newline at end of file
diff --git a/doc/examples/use-case-8.txt b/doc/examples/use-case-8.txt
index 74665dd..ee36fd6 100644
--- a/doc/examples/use-case-8.txt
+++ b/doc/examples/use-case-8.txt
@@ -1 +1,2 @@
-fun f = f(3) * x * 4 + 3;
\ No newline at end of file
+fun f = f(3) * x * 4 + 3;
+fun g =  f(3) + f'(3)*(x-3) + f''(3)/2 * (x-3)^2 + f'''(3) / 6 * (x-3)^3 + f''''(3) / 24 * (x-3)^4;
\ No newline at end of file
diff --git a/doc/examples/use-case-9.txt b/doc/examples/use-case-9.txt
index d5e2324..9d8dcfa 100644
--- a/doc/examples/use-case-9.txt
+++ b/doc/examples/use-case-9.txt
@@ -1,4 +1,4 @@
 fun f = x^2;
-var a = int f 0 ~ 5;
-var b = int f 0 ~ 1 + int f 1 ~ 2 + int f 2 ~ 3 + int f 3 ~ 4 + int f 4 ~ 5;
+var a = int f (0 ~ 5);
+var b = int f (0 ~ 1) + int f (1 ~ 2) + int f (2 ~ 3) + int f (3 ~ 4) + int f (4 ~ 5);
 var c = a - b;
\ No newline at end of file
diff --git a/src/frontend/lexical-analysis/flex-actions.h b/src/frontend/lexical-analysis/flex-actions.h
index a0ae637..7cca08e 100644
--- a/src/frontend/lexical-analysis/flex-actions.h
+++ b/src/frontend/lexical-analysis/flex-actions.h
@@ -62,7 +62,7 @@ typedef enum TokenID {
 	LESSER_EQUAL,
 	GREATER,
 	GREATER_EQUAL,
-	COMPARE,
+	NOT_EQUAL,
 	VAR,
 	ERR,
 	TAYLOR,
diff --git a/src/frontend/lexical-analysis/flex-patterns.l b/src/frontend/lexical-analysis/flex-patterns.l
index ec63843..f5a65cf 100644
--- a/src/frontend/lexical-analysis/flex-patterns.l
+++ b/src/frontend/lexical-analysis/flex-patterns.l
@@ -20,7 +20,6 @@ char            [a-zA-Z]
 characters      [a-zA-Z., ]
 decimal         [.]
 endline			\n
-/* whitespace		[\f\n\r\t\v\0 ] */
 whitespace      [ \f\n\r\t\v]
 
 %%
@@ -54,6 +53,7 @@ whitespace      [ \f\n\r\t\v]
 "<="                                        { return LESSER_EQUAL; }
 ">"                                         { return GREATER; }
 ">="                                        { return GREATER_EQUAL; }
+"!="                                        { return NOT_EQUAL; }
 "in"                                        { return IN; }
 "{"                                         { return OPEN_BRACES; }
 "}"                                         { return CLOSE_BRACES; }
diff --git a/src/frontend/syntactic-analysis/bison-actions.c b/src/frontend/syntactic-analysis/bison-actions.c
index 8b10194..f842c11 100644
--- a/src/frontend/syntactic-analysis/bison-actions.c
+++ b/src/frontend/syntactic-analysis/bison-actions.c
@@ -10,13 +10,13 @@
 
 void yyerror(const char * string) {
 	LogError("Mensaje: '%s' debido a '%s' (linea %d).", string, yytext, yylineno);
-	LogError("En ASCII es:");
-	LogErrorRaw("\t");
-	const int length = strlen(yytext);
-	for (int i = 0; i < length; ++i) {
-		LogErrorRaw("[%d]", yytext[i]);
-	}
-	LogErrorRaw("\n\n");
+	// LogError("En ASCII es:");
+	// LogErrorRaw("\t");
+	// const int length = strlen(yytext);
+	// for (int i = 0; i < length; ++i) {
+	// 	LogErrorRaw("[%d]", yytext[i]);
+	// }
+	// LogErrorRaw("\n\n");
 }
 
 int ProgramGrammarAction(const int value) {
diff --git a/src/frontend/syntactic-analysis/bison-grammar.y b/src/frontend/syntactic-analysis/bison-grammar.y
index 2637de0..5a5b518 100644
--- a/src/frontend/syntactic-analysis/bison-grammar.y
+++ b/src/frontend/syntactic-analysis/bison-grammar.y
@@ -50,7 +50,7 @@
 %token LESSER_EQUAL
 %token GREATER
 %token GREATER_EQUAL
-%token COMPARE
+%token NOT_EQUAL
 %token VAR
 %token ERR
 %token TAYLOR
@@ -61,8 +61,9 @@
 %token STRING
 
 // Reglas de asociatividad y precedencia (de menor a mayor):
-%left ADD SUB
-%left MUL DIV
+%left GREATER GREATER_EQUAL LESSER LESSER_EQUAL EQUAL NOT_EQUAL
+%left ADD SUB NOT
+%left MUL DIV AND OR
 %left POW
 
 %%
@@ -70,50 +71,60 @@
 program: statements												 { $$ = ProgramGrammarAction($1); }
 	;
 
-expression: constant
+statement: evaluate SEMICOLON
+	| integrate SEMICOLON
+	| derivative SEMICOLON
+	| declare_function SEMICOLON
+	| if_statement
+	| ifelse_statement
+	| for_statement
+	| while_statement
+	| printCSV SEMICOLON
+	| print SEMICOLON
+	| declare_variable SEMICOLON
+	| assign_variable SEMICOLON
+	;
+
+expression: positive_constant
  	| evaluate
 	| integrate
 	| derivative
 	| STRING
-	| expression ADD expression						 			
-	| expression SUB expression									
+	| expression ADD expression
+	| expression SUB expression
 	| expression MUL expression
 	| expression DIV expression
 	| expression POW expression
 	| OPEN_PARENTHESIS expression CLOSE_PARENTHESIS
 	| SUB expression
-	| number
 	;
 
-domain: STRING LESSER number
-	| STRING LESSER_EQUAL number
-	| STRING GREATER number
-	| STRING GREATER_EQUAL number
-	| STRING EQUAL number
-	| number LESSER STRING
-	| number LESSER_EQUAL STRING
-	| number GREATER STRING
-	| number GREATER_EQUAL STRING
-	| number EQUAL STRING
-	| number LESSER STRING LESSER number
-	| number LESSER_EQUAL STRING LESSER number
-	| number LESSER STRING LESSER_EQUAL number
-	| number LESSER_EQUAL STRING LESSER_EQUAL number 
+domain: expression LESSER expression
+	| expression LESSER_EQUAL expression
+	| expression GREATER expression
+	| expression GREATER_EQUAL expression
+	| expression EQUAL expression
+	| expression NOT_EQUAL expression
+	| expression LESSER expression LESSER expression
+	| expression LESSER_EQUAL expression LESSER expression
+	| expression LESSER expression LESSER_EQUAL expression
+	| expression LESSER_EQUAL expression LESSER_EQUAL expression
 	;
 
-boolean: number LESSER number
-	| number LESSER_EQUAL number
-	| number GREATER number
-	| number GREATER_EQUAL number
-	| number EQUAL number
+boolean: expression LESSER expression
+	| expression LESSER_EQUAL expression
+	| expression GREATER expression
+	| expression GREATER_EQUAL expression
+	| expression EQUAL expression
+	| expression NOT_EQUAL expression
 	| boolean OR boolean
 	| boolean AND boolean
+	| OPEN_PARENTHESIS boolean CLOSE_PARENTHESIS
 	| NOT boolean
 	;
 
-constant: DOUBLE
+positive_constant: DOUBLE
 	| INTEGER
-	| SUB constant
 	;
 
 declare_function: FUNCTION STRING ASSIGN function
@@ -134,15 +145,15 @@ composite: STRING COMPOSITE STRING
 	| composite COMPOSITE STRING
 	;
 
-numbers: number
-	| number COMMA numbers
+expressions: expression
+	| expression COMMA expressions
 	;
 
 strings: STRING
 	| STRING COMMA strings
 	;
 
-numArray: OPEN_BRACKETS numbers CLOSE_BRACKETS
+numArray: OPEN_BRACKETS expressions CLOSE_BRACKETS
 	;
 
 numArrays: numArray
@@ -166,41 +177,26 @@ escapeStrings: escapeString
 escapeStringArray: OPEN_BRACKETS escapeStrings CLOSE_BRACKETS
 	;
 
-evaluate: EVALUATE STRING IN number
+evaluate: EVALUATE STRING IN OPEN_PARENTHESIS expression CLOSE_PARENTHESIS
 	| EVALUATE STRING IN numArray
-	| STRING OPEN_PARENTHESIS number CLOSE_PARENTHESIS
-	| EVALUATE stringArray IN number
+	| STRING OPEN_PARENTHESIS expression CLOSE_PARENTHESIS
+	| EVALUATE stringArray IN OPEN_PARENTHESIS expression CLOSE_PARENTHESIS
 	| EVALUATE stringArray IN numArray
-	| stringArray OPEN_PARENTHESIS number CLOSE_PARENTHESIS
+	| stringArray OPEN_PARENTHESIS expression CLOSE_PARENTHESIS
 	;
 
-integrate: INTEGRATE STRING BETWEEN number AND_INT number
-	| INTEGRATE STRING number AND_INT number
-	| INTEGRATE stringArray BETWEEN number AND_INT number
-	| INTEGRATE stringArray number AND_INT number
-	| integrate ERR constant
+integrate: INTEGRATE STRING BETWEEN OPEN_PARENTHESIS expression AND_INT expression CLOSE_PARENTHESIS
+	| INTEGRATE STRING OPEN_PARENTHESIS expression AND_INT expression CLOSE_PARENTHESIS
+	| INTEGRATE stringArray BETWEEN OPEN_PARENTHESIS expression AND_INT expression CLOSE_PARENTHESIS
+	| INTEGRATE stringArray OPEN_PARENTHESIS expression AND_INT expression CLOSE_PARENTHESIS
+	| integrate ERR positive_constant
 	;
 
 squotes: SQUOTE
 	| SQUOTE squotes
 	; 
 
-statement: evaluate SEMICOLON
-	| integrate SEMICOLON
-	| derivative SEMICOLON
-	| declare_function SEMICOLON
-	| if_statement
-	| ifelse_statement
-	| for_statement
-	| while_statement
-	| printCSV SEMICOLON
-	| print SEMICOLON
-	| declare_variable SEMICOLON
-	| assign_variable SEMICOLON
-	;
-
-print: PRINT OPEN_PARENTHESIS number CLOSE_PARENTHESIS
-	| PRINT OPEN_PARENTHESIS STRING CLOSE_PARENTHESIS
+print: PRINT OPEN_PARENTHESIS expression CLOSE_PARENTHESIS
 	| PRINT OPEN_PARENTHESIS escapeString CLOSE_PARENTHESIS
 	;
 
@@ -208,13 +204,13 @@ statements: statement
 	| statement statements
 	;
 
-derivative: DERIVATIVE STRING IN constant
-	| DERIVATIVE INTEGER STRING IN constant
-	| STRING squotes OPEN_PARENTHESIS constant CLOSE_PARENTHESIS
-	| DERIVATIVE stringArray IN constant
-	| DERIVATIVE INTEGER stringArray IN constant
-	| stringArray squotes OPEN_PARENTHESIS constant CLOSE_PARENTHESIS
-	| derivative ERR constant
+derivative: DERIVATIVE STRING IN OPEN_PARENTHESIS expression CLOSE_PARENTHESIS
+	| DERIVATIVE INTEGER STRING IN OPEN_PARENTHESIS expression CLOSE_PARENTHESIS
+	| STRING squotes OPEN_PARENTHESIS expression CLOSE_PARENTHESIS
+	| DERIVATIVE stringArray IN OPEN_PARENTHESIS expression CLOSE_PARENTHESIS
+	| DERIVATIVE INTEGER stringArray IN OPEN_PARENTHESIS expression CLOSE_PARENTHESIS
+	| stringArray squotes OPEN_PARENTHESIS expression CLOSE_PARENTHESIS
+	| derivative ERR positive_constant
 	;
 
 if_statement: IF OPEN_PARENTHESIS boolean CLOSE_PARENTHESIS OPEN_BRACKETS statements CLOSE_BRACKETS
@@ -245,23 +241,23 @@ declare_variable: VAR STRING
 printCSV: PRINTCSV OPEN_PARENTHESIS escapeStringArray COMMA arrayNumArray COMMA escapeString CLOSE_PARENTHESIS
 	;
 
-number: constant
+/* expression: positive_constant
  	| evaluate
 	| integrate
 	| derivative
-	| number ADD number
-	| number DIV number
-	| number SUB number
-	| number POW number
-	| number MUL number
-	| SUB number
-	| OPEN_PARENTHESIS number CLOSE_PARENTHESIS
-	;
+	| expression ADD expression
+	| expression DIV expression
+	| expression SUB expression
+	| expression POW expression
+	| expression MUL expression
+	| SUB expression
+	| OPEN_PARENTHESIS expression CLOSE_PARENTHESIS
+	; */
 
-assign_variable: STRING ADD_ASSIGN number
-	| STRING SUB_ASSIGN number
-	| STRING MUL_ASSIGN number
-	| STRING DIV_ASSIGN number
+assign_variable: STRING ADD_ASSIGN expression
+	| STRING SUB_ASSIGN expression
+	| STRING MUL_ASSIGN expression
+	| STRING DIV_ASSIGN expression
 	| STRING INCREMENT
 	| STRING DECREMENT
 	| STRING ASSIGN expression
diff --git a/src/main.c b/src/main.c
index 85e8f3d..2fc7882 100644
--- a/src/main.c
+++ b/src/main.c
@@ -13,6 +13,7 @@ const int main(const int argumentCount, const char ** arguments) {
 	// #ifdef YYDEBUG
 	//  	yydebug = 1;
 	// #endif
+
 	// Inicializar estado de la aplicación.
 	state.result = 0;
 	state.succeed = false;