Language: C

#include <stdio.h>
int main(void){
    int a, b, c;
    a = 1;
    for(b=1;b<10;b++){
       c = a * b;
       printf("%dx%d=%d\n", a, b, c);
    }
    int a, b, c;
    a = 2;
    for(b=1;b<10;b++){
       c = a * b;
       printf("%dx%d=%d\n", a, b, c);
    }
    int a, b, c;
    a = 3;
    for(b=1;b<10;b++){
       c = a * b;
       printf("%dx%d=%d\n", a, b, c);
    }
    int a, b, c;
    a = 4;
    for(b=1;b<10;b++){
       c = a * b;
       printf("%dx%d=%d\n", a, b, c);
    }
    int a, b, c;
    a = 5;
    for(b=1;b<10;b++){
       c = a * b;
       printf("%dx%d=%d\n", a, b, c);
    }
    int a, b, c;
    a = 6;
    for(b=1;b<10;b++){
       c = a * b;
       printf("%dx%d=%d\n", a, b, c);
    }
    int a, b, c;
    a = 7;
    for(b=1;b<10;b++){
       c = a * b;
       printf("%dx%d=%d\n", a, b, c);
    }
    int a, b, c;
    a = 8;
    for(b=1;b<10;b++){
       c = a * b;
       printf("%dx%d=%d\n", a, b, c);
    }
    int a, b, c;
    a = 9;
    for(b=1;b<10;b++){
       c = a * b;
       printf("%dx%d=%d\n", a, b, c);
    }

Compiler output:
main.c: In function 'main':
main.c:9:9: error: redeclaration of 'a' with no linkage
    9 |     int a, b, c;
      |         ^
main.c:3:9: note: previous declaration of 'a' with type 'int'
    3 |     int a, b, c;
      |         ^
main.c:9:12: error: redeclaration of 'b' with no linkage
    9 |     int a, b, c;
      |            ^
main.c:3:12: note: previous declaration of 'b' with type 'int'
    3 |     int a, b, c;
      |            ^
main.c:9:15: error: redeclaration of 'c' with no linkage
    9 |     int a, b, c;
      |               ^
main.c:3:15: note: previous declaration of 'c' with type 'int'
    3 |     int a, b, c;
      |               ^
main.c:15:9: error: redeclaration of 'a' with no linkage
   15 |     int a, b, c;
      |         ^
main.c:9:9: note: previous declaration of 'a' with type 'int'
    9 |     int a, b, c;
      |         ^
main.c:15:12: error: redeclaration of 'b' with no linkage
   15 |     int a, b, c;
      |            ^
main.c:9:12: note: previous declaration of 'b' with type 'int'
    9 |     int a, b, c;
      |            ^
main.c:15:15: error: redeclaration of 'c' with no linkage
   15 |     int a, b, c;
      |               ^
main.c:9:15: note: previous declaration of 'c' with type 'int'
    9 |     int a, b, c;
      |               ^
main.c:21:9: error: redeclaration of 'a' with no linkage
   21 |     int a, b, c;
      |         ^
main.c:15:9: note: previous declaration of 'a' with type 'int'
   15 |     int a, b, c;
      |         ^
main.c:21:12: error: redeclaration of 'b' with no linkage
   21 |     int a, b, c;
      |            ^
main.c:15:12: note: previous declaration of 'b' with type 'int'
   15 |     int a, b, c;
      |            ^
main.c:21:15: error: redeclaration of 'c' with no linkage
   21 |     int a, b, c;
      |               ^
main.c:15:15: note: previous declaration of 'c' with type 'int'
   15 |     int a, b, c;
      |               ^
main.c:27:9: error: redeclaration of 'a' with no linkage
   27 |     int a, b, c;
      |         ^
main.c:21:9: note: previous declaration of 'a' with type 'int'
   21 |     int a, b, c;
      |         ^
main.c:27:12: error: redeclaration of 'b' with no linkage
   27 |     int a, b, c;
      |            ^
main.c:21:12: note: previous declaration of 'b' with type 'int'
   21 |     int a, b, c;
      |            ^
main.c:27:15: error: redeclaration of 'c' with no linkage
   27 |     int a, b, c;
      |               ^
main.c:21:15: note: previous declaration of 'c' with type 'int'
   21 |     int a, b, c;
      |               ^
main.c:33:9: error: redeclaration of 'a' with no linkage
   33 |     int a, b, c;
      |         ^
main.c:27:9: note: previous declaration of 'a' with type 'int'
   27 |     int a, b, c;
      |         ^
main.c:33:12: error: redeclaration of 'b' with no linkage
   33 |     int a, b, c;
      |            ^
main.c:27:12: note: previous declaration of 'b' with type 'int'
   27 |     int a, b, c;
      |            ^
main.c:33:15: error: redeclaration of 'c' with no linkage
   33 |     int a, b, c;
      |               ^
main.c:27:15: note: previous declaration of 'c' with type 'int'
   27 |     int a, b, c;
      |               ^
main.c:39:9: error: redeclaration of 'a' with no linkage
   39 |     int a, b, c;
      |         ^
main.c:33:9: note: previous declaration of 'a' with type 'int'
   33 |     int a, b, c;
      |         ^
main.c:39:12: error: redeclaration of 'b' with no linkage
   39 |     int a, b, c;
      |            ^
main.c:33:12: note: previous declaration of 'b' with type 'int'
   33 |     int a, b, c;
      |            ^
main.c:39:15: error: redeclaration of 'c' with no linkage
   39 |     int a, b, c;
      |               ^
main.c:33:15: note: previous declaration of 'c' with type 'int'
   33 |     int a, b, c;
      |               ^
main.c:45:9: error: redeclaration of 'a' with no linkage
   45 |     int a, b, c;
      |         ^
main.c:39:9: note: previous declaration of 'a' with type 'int'
   39 |     int a, b, c;
      |         ^
main.c:45:12: error: redeclaration of 'b' with no linkage
   45 |     int a, b, c;
      |            ^
main.c:39:12: note: previous declaration of 'b' with type 'int'
   39 |     int a, b, c;
      |            ^
main.c:45:15: error: redeclaration of 'c' with no linkage
   45 |     int a, b, c;
      |               ^
main.c:39:15: note: previous declaration of 'c' with type 'int'
   39 |     int a, b, c;
      |               ^
main.c:51:9: error: redeclaration of 'a' with no linkage
   51 |     int a, b, c;
      |         ^
main.c:45:9: note: previous declaration of 'a' with type 'int'
   45 |     int a, b, c;
      |         ^
main.c:51:12: error: redeclaration of 'b' with no linkage
   51 |     int a, b, c;
      |            ^
main.c:45:12: note: previous declaration of 'b' with type 'int'
   45 |     int a, b, c;
      |            ^
main.c:51:15: error: redeclaration of 'c' with no linkage
   51 |     int a, b, c;
      |               ^
main.c:45:15: note: previous declaration of 'c' with type 'int'
   45 |     int a, b, c;
      |               ^
main.c:56:5: error: expected declaration or statement at end of input
   56 |     }
      |     ^