diff --git a/is_prime 1.1/main b/is_prime 1.1/main
new file mode 100644
index 0000000..57d01f8
Binary files /dev/null and b/is_prime 1.1/main differ
diff --git a/is_prime 1.1/main.c b/is_prime 1.1/main.c
new file mode 100644
index 0000000..b6de7d6
--- /dev/null
+++ b/is_prime 1.1/main.c	
@@ -0,0 +1,51 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include "turing.h"
+#include "states.h"
+#include "const.h"
+
+#define REJECT -1
+#define ACCEPT -2
+
+// gcc -g main.c turing.c states.c turing.h states.h const.h -o main
+
+int main(){
+
+	int List[] = {0,5,1,8,7,7,7,2,2,2,2,9};
+	// Enough sevens that we can later add more 1s.
+	// We could have between (sqrt(m)-2) and (m-2) 7s 
+	// But Nuño, if you put sqrt(m) -2 sevens, aren't you offloading the calculation to yourself instead making the machine calculate it?
+	// Yes, I am.
+	int longitud=length(List);
+	
+	fprintf(stdout,"\nEsta función acepta cuando n es primo");
+	
+	int state=0;
+	int position=0;
+	int symbol= List[position];
+	int movement =0; // undefined.
+	int placeholder;	
+	
+
+	while(state!=ACCEPT && state!=REJECT){
+		
+		print_linea();
+		print_variables(state,position,symbol, movement);		
+		print_lista(List, longitud, position);
+
+		fscanf(stdin,"\n%d", &placeholder);
+
+		carry_out_step(&symbol,&state,&movement);
+		
+		List[position]=symbol;
+		position = position +movement;	
+		symbol=List[position];
+		
+	}
+	
+	print_linea();
+	print_variables(state,position,symbol, movement);		
+	print_lista(List, longitud, position);
+
+
+}
diff --git a/is_prime 1.1/states.c b/is_prime 1.1/states.c
new file mode 100644
index 0000000..736e484
--- /dev/null
+++ b/is_prime 1.1/states.c	
@@ -0,0 +1,364 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include "const.h"
+#include "states.h"
+
+// States of a Turing Machine that checks whether a number DOESN'T divide another number
+// NTS: Check that the first number is smaller? Actually not necessary: see state 2.
+
+/*
+Initially, I defined a triplet, which was what the different states, which are functions returned.
+
+typedef struct  {
+
+	int state; // Finite list of states: initial (0), state 1, state 2, state 3, ..., state 7.
+	int symbol; // Finite list of symbols: 0,1,2,3,4,5,6,7,8,9
+	int movement; // Left = -1, Right =1;
+
+}  ssm;
+
+But I thought that modifying pointers was easier and more elegant.
+*/
+
+void state0(int *symbol, int *state, int *movement);
+void state1(int *symbol, int *state, int *movement);
+void state2(int *symbol, int *state, int *movement);
+void state3(int *symbol, int *state, int *movement);
+void state4(int *symbol, int *state, int *movement);
+void state5(int *symbol, int *state, int *movement);
+void state6(int *symbol, int *state, int *movement);
+void state7(int *symbol, int *state, int *movement);
+void state8(int *symbol, int *state, int *movement);
+/*void state9(int *symbol, int *state, int *movement);
+void state10(int *symbol, int *state, int *movement);
+*/
+// This function is the delta of which Kozen speaks of in p.210 &ss in Automata and Computability.
+void carry_out_step(int *symbol, int *state, int *movement){  // I could make this a bigger if/else tree, but I don't want to.
+// Initially, I thought to use https://stackoverflow.com/questions/840501/how-do-function-pointers-in-c-work, but this proved unnecessary.
+	
+	if(*state==0){
+		state0(symbol,state, movement);
+	}
+	else if(*state==1){ 
+	// Nótese que los else ifs son necesarios, porque después de state0, *state es =1, pero queremos que se de cuenta en la siguiente vuelta
+		state1(symbol,state, movement);
+	}
+	else if(*state==2){
+		state2(symbol,state, movement);
+	}
+	else if(*state==3){
+		state3(symbol,state, movement);
+	}
+	else if(*state==4){
+		state4(symbol,state, movement);
+	}
+	else if(*state==5){
+		state5(symbol,state, movement);
+	}
+	
+	else if(*state==6){
+		state6(symbol,state, movement);
+	}	
+
+	else if(*state==7){
+		state7(symbol,state, movement);
+	}
+
+	else if(*state==8){
+		state8(symbol,state, movement);
+	}
+	/*
+	else if(*state==9){
+		state9(symbol,state, movement);
+	}
+	else if(*state==10){
+		state10(symbol,state, movement);
+	}
+*/
+}
+
+void state0(int *symbol, int *state, int *movement){
+	if(*symbol ==0){
+		*symbol=0; // This is the left endmarker. It isn't changed. This line could be ommited.
+		*movement= 1; // Move to the right (0 would be to the left).
+		*state=1; // Change to state 1.
+	}
+
+	else{
+		*state = REJECT; // This is defined as a constant in const.h 
+		// The program ends, because it has unspecified behaviour
+		*movement= 0;
+	}
+
+}
+
+void state1(int *symbol, int *state, int *movement){
+	if(*symbol ==1){
+		*symbol=3; // Another symbol.
+		*movement= 1; // Move to the right (-1 would be to the left).
+		*state=2; // Change to state 2.
+	}
+
+	else if(*symbol ==3){  // Note that we need an else because otherwise after it changes a 1 to a 3, symbol=3 and it goes back to state1.
+	// Note that we have inadvertently created a function to see whether m is(n't) k modulo n; we would only have to start with n-k 3s at the beginning
+		*symbol=3;
+		*movement= 1; 
+		*state=1; 
+	}
+	
+	else if(*symbol ==8){ // 8 = X
+		*symbol=8;
+		*movement= 1; 
+		*state=4; 
+	}
+	
+	else{
+		*symbol=*symbol;
+		*movement= 1; 
+		*state=1; 
+	}
+}
+
+void state2(int *symbol, int *state, int *movement){
+
+	if(*symbol ==2){
+		*symbol=4; 
+		*movement= -1; 
+		*state=3; 
+	}
+
+	else if(*symbol ==9){
+		*symbol=9; 
+		*movement= -1; 
+		*state=7; 
+	}
+
+	else{
+		*symbol=*symbol;
+		*movement= 1; 
+		*state=2; 
+	}
+}
+
+void state3(int *symbol, int *state, int *movement){
+
+	if(*symbol ==0){
+		*symbol=0; 
+		*movement= 1; 
+		*state=1; 
+	}
+
+	else {
+		*symbol=*symbol;
+		*movement = -1;
+		*state= 3;
+	}
+}
+
+void state4(int *symbol, int *state, int *movement){
+
+	if(*symbol ==2){
+		*symbol=4; 
+		*movement=-1; 
+		*state=5;
+	}
+
+	else if(*symbol ==9){
+		*symbol=9; 
+		*movement=-1;  // Only because it rejects
+		*state = 6; 
+	}
+
+	else{
+		*symbol = *symbol;
+		*movement =1;
+		*state=4;
+	}
+
+}
+
+void state5(int *symbol, int *state, int *movement){
+	// Note that after state 4, the TM is in m-territory.
+	if(*symbol ==3){
+		*symbol=1; 
+		*movement=-1; 
+		*state=5; 
+	}
+	
+	else if(*symbol ==5){
+		*symbol=6; 
+		*movement= -1; 
+		*state = 5; 
+	}
+
+	else if(*symbol ==0){
+		*symbol=0; 
+		*movement= 1; 
+		*state = 1; 
+	}
+
+	else{
+		*symbol = *symbol;
+		*movement =-1;
+		*state=5;
+	}
+
+}
+
+void state6(int *symbol, int *state, int *movement){
+	if(*symbol ==5){
+		*symbol=5; 
+		*movement=0; // Only because it accepts. And it accepts because the first divisor of m is m.
+		*state=ACCEPT; 
+		fprintf(stdout, "\nIt accepts because the first time that n fits in m, it reaches the end of m, so n=m. \n");
+	}
+
+	else if(*symbol ==6){
+		*symbol=6;
+		*movement= 0; // When the function ends, I want it to stay in the same place. But ultimately it doesn't matter.
+		*state = REJECT; 
+		fprintf(stdout, "\nIt rejects because m is bigger than n and n | m.\n");
+	}
+
+	else if (*symbol !=6 && *symbol !=5){
+		*symbol = *symbol;
+		*movement =-1;
+		*state=6;
+	}
+
+}
+
+void state7(int *symbol, int *state, int *movement){
+	if(*symbol ==4){
+		*symbol=2; 
+		*movement=-1;
+		*state=7;
+	}
+
+	else if(*symbol ==3){
+		*symbol=1;
+		*movement= -1;
+		*state = 7;
+	}
+	else if(*symbol ==6){
+		*symbol=5;
+		*movement= -1;
+		*state = 7;
+	}
+	else if(*symbol ==0){
+		*symbol=0;
+		*movement= 1;
+		*state = 8;
+	}
+	else{
+		*symbol=*symbol;
+		*movement= -1;
+		*state = 7;
+	}
+
+}
+
+void state8(int *symbol, int *state, int *movement){
+	if(*symbol ==8){
+		*symbol=1; 
+		*movement=1;
+		*state=8;
+	}
+
+	else if(*symbol ==7){
+		*symbol=8;
+		*movement= -1;
+		*state = 3;
+	}
+	else if(*symbol ==2){
+		*symbol=2;
+		*movement= 0;
+		*state = ACCEPT;
+	}
+	else{
+		*symbol=*symbol;
+		*movement= 1;
+		*state = 8;
+	}
+
+}
+
+/*
+void state8(int *symbol, int *state, int *movement){
+
+	if(*symbol ==4){
+		*symbol=2; 
+		*movement=-1; 
+		*state=8; 
+	}
+
+	else if(*symbol ==3){
+		*symbol=1; 
+		*movement= -1; 
+		*state = 8; 
+	}
+
+	else if(*symbol ==0){
+		*symbol=0; 
+		*movement= 1; 
+		*state = 9; 
+	}
+
+
+	else{
+		*symbol = *symbol;
+		*movement =-1;
+		*state=8;
+	}
+
+}
+
+void state9(int *symbol, int *state, int *movement){
+
+	if(*symbol ==8){
+		*symbol=1; 
+		*movement=1; 
+		*state=9; 
+	}
+
+	else if(*symbol ==5){
+		*symbol=8; 
+		*movement= 1; 
+		*state = 10; 
+	}
+
+	else if(*symbol ==2){
+		*symbol=2; 
+		*movement= 0;  // Only because it accepts
+		*state = ACCEPT; 
+	}
+
+	else if(*symbol ==4){
+		*symbol=4; 
+		*movement= 0;  // Only because it accepts
+		*state = ACCEPT; 
+	}
+
+	else{
+		*symbol = *symbol;
+		*movement =1;
+		*state=9;
+	}
+
+}
+
+void state10(int *symbol, int *state, int *movement){
+
+	if(*symbol ==0){
+		*symbol=0; 
+		*movement=1; 
+		*state=1; 
+	}
+
+	else {
+		*symbol = *symbol;
+		*movement =-1;
+		*state=10;
+	}
+
+}*/
diff --git a/is_prime 1.1/states.h b/is_prime 1.1/states.h
new file mode 100644
index 0000000..625b918
--- /dev/null
+++ b/is_prime 1.1/states.h	
@@ -0,0 +1,6 @@
+#ifndef __STATES_H_
+#define __STATES_H_
+
+void carry_out_step(int *symbol, int *state, int *movement); // This is the only function I'm going to need to use outside of states.c
+
+#endif
diff --git a/is_prime 1.1/states.o b/is_prime 1.1/states.o
new file mode 100644
index 0000000..1e33186
Binary files /dev/null and b/is_prime 1.1/states.o differ
diff --git a/is_prime 1.1/turing.c b/is_prime 1.1/turing.c
new file mode 100644
index 0000000..e9a38a4
--- /dev/null
+++ b/is_prime 1.1/turing.c	
@@ -0,0 +1,85 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include "turing.h"
+#include "const.h"
+
+// Turing print defines functions that take a list, take a position in that list and print the list with a pointer to that position.
+// It prints this vertically
+
+int length(int *List){
+	int i =0;
+	
+	while (List[i]<9){ // Por cómo construimos nuestras listas.
+		i=i+1;
+	}
+
+	/*Anecdóticamente, el siguiente código da error.
+	i=0;	
+	while (List[i]<=9){ 
+		i=i+1;
+	}	
+	Y lo hace porque al asignar un trozo de memoria, 
+	si la lista tiene, p.ej., longitud 6, 
+	List[0] hasta Lista[5] son la lista de verdad, 
+	pero Lista[6] <9, y la sigue contando.
+	*/
+
+	return i+1;
+}
+
+void print_lista(int*L, int length, int position){
+	if(L==NULL || length <= position){
+		fprintf(stdout, "\nError en prettyprint");
+	}
+	else{
+		int i=0;
+		char tabs[]="\t\t\t\t\t\t\t\0";	
+		for(i=0; i<length; i++){
+			if(i==position){
+				fprintf(stdout, "\n%s{",tabs);
+			}
+			else{
+				fprintf(stdout, "\n%s",tabs);
+			}
+
+			if( L[i]==0){
+					fprintf(stdout, "T");
+
+			}
+
+			else if(L[i]==8){
+					fprintf(stdout, "X");
+			}
+
+			else if(L[i]==9){
+					fprintf(stdout, "W");
+			}
+
+			else{
+					fprintf(stdout, "%d",L[i]);
+			}
+
+			if(i==position){
+				fprintf(stdout, "}\n");
+			}
+			else{
+				fprintf(stdout, "\n");
+			}
+		}
+
+	}
+
+}
+
+void print_variables(int state, int position, int symbol,  int movement){
+	char tabs[]="\t\t\t\t\t\t\t\0";	
+	fprintf(stdout,"\n%sState =%d\n",tabs,state);
+	fprintf(stdout,"\n%sPosition =%d\n",tabs,position);
+	fprintf(stdout,"\n%sSymbol =%d\n",tabs,symbol);
+	fprintf(stdout,"\n%sMovement =%d\n\n",tabs,movement);
+}
+
+void print_linea(){
+	char tabs[]="\t\t\0";	
+	fprintf(stdout,"\n%s__________________________________________________________________________________________\n",tabs);
+}
diff --git a/is_prime 1.1/turing.h b/is_prime 1.1/turing.h
new file mode 100644
index 0000000..e115c7c
--- /dev/null
+++ b/is_prime 1.1/turing.h	
@@ -0,0 +1,8 @@
+#ifndef __CONST_H_
+#define __CONST_H_
+
+void print_lista(int*L, int length, int position);
+void print_variables(int state, int position, int symbol,  int movement);
+int length(int *List);
+void print_linea();
+#endif