//* Demonstrates: How to use efficiently exclusive if-else cases *
#include <stdio.h>

int main() {
    double ph;

    printf("Welcome to a simple chemical expert system:\n");
    printf("Please specify the PH for the substance.\n");

    printf("ph=");
    scanf("%lf", &ph);

    if (ph<6.9)
        if (ph<3.5)             printf("It is very acidic!\a\n");
        else                    printf("It is acidic.\n");
    else
        if (ph<7.1)             printf("It is about neutral.\n");
        else
            if (ph<=9.5)        printf("It is basic.\n");
            else                printf("It is very basic!\a.\n");

    return(0);
}