Moved cond.c to folder LC21

Appendix1/Assertion/Assertions.c

@@ -0,0 +1,18 @@
+#include <stdio.h>
+#include <assert.h>
+
+int main()
+{
+    int x = 7;
+
+    /*  Some big code in between and let's say x
+       is accidentally changed to 9  */
+    x = 9;
+
+    // Programmer assumes x to be 7 in rest of the code
+    assert(x==7);
+
+    /* Rest of the code */
+
+    return 0;
+}