The instructions are to make sure that this loop runs indefinitely unless someone enters 0 in either the op, a, or b variables. How would I go about doing that? Because right now it can't go further than one equation inputted.

Here's the code:

```
#include <iostream>
#include <string>
#include <cmath>
#include <math.h> 
#include <stdlib.h>
using namespace std;
void calculate(float a, char op, float b);//used this function so it can be called later by the function below. 

int main(){
   void calculate(float a, char op, float b);
    float a, b; //variables for equation
    char op;// for operator 
    cout << "Enter your equation: ";
    if (cin >> a>> op >> b)
      calculate(a, op, b);

}

void calculate(float a, char op, float b){

  if (a==0 || b==0 || op==0) {
    EXIT_SUCCESS;
  }

  switch(op) {
    case '+':
      cout << "\nAddition of two numbers is " << (a + b);
      break;
    case '-':
      cout << "\nSubtraction of two numbers is " << (a - b);
      break;
    case '*':
      cout << "\nMultiplication of two numbers is "<< (a * b);
      break;
    case '/':
      cout << "\nDivision of two numbers is "<< (a / b);
      break;
    case '^':
      cout<<"\nExponent of two numbers is "<< pow(a,b);
      break;
    case '%':
      cout<<"\nRemainder(modulus) of these two numbers is" << ( (int)a %  int (b));
    case 'v':
      cout << "The square root of the number is : " << sqrt(a);
      if (b!=0) {
        cout << "More than one entry detected." << endl;
      }
    default:
      cout<< "\nUnkown operator!";
    }

  }

```