Inverted syntax with conditional expressions

In traditional syntax conditional expressions are usually shown before the action within a statement or code block:

 IF raining=true THEN needumbrella=true 
In inverted syntax, the action is listed before the conditional expression in the statement or code block:

 needumbrella=true IF raining=true 
Inverted syntax with assignment

In traditional syntax, assignments are usually expressed with the variable appearing before the expression:

 a = 6
In inverted syntax, the expression appears before the variable:

 6 = a
Task

The task is to demonstrate support for inverted syntax forms within the language by showing both the traditional and inverted forms.

 
#include <stdio.h>
#include <stdlib.h>
#define otherwise       do { register int _o = 2; do { switch (_o) {  case 1:
#define given(Mc)       ;case 0: break; case 2: _o = !!(Mc); continue; } break; } while (1); } while (0)
 
 
int foo() { return 1; }
 
main()
{
        int a = 0;
 
        otherwise  a = 4 given (foo());
        printf("%d\n", a);
        exit(0);
}
 