Book Updates

-add traceback info in 6.1

Author: ktechhydle

book/chapter6.1.md

@@ -16,30 +16,62 @@ And the output:
 
 ```sh
 error: division by zero
-   in: example.glang:1:6
-   +
-   |
-   | 1 / 0;
-   |     ^
-   |
-   +
-process finished with exit code -1
+    --> example.glang:1:6
+     |
+   1 | 1 / 0;
+     |     ^
 ```
 
 ## What The Error Says
 
 GLang highlights _exactly_ where things went wrong, showing you the offending line and character.
 
+- `error:` tells you what error occured.
+- `-->` indicates where and what file caused the issue.
+- `^` shows what code stopped the program's execution
+
 Sometimes, you’ll also get a helpful hint to steer you in the right direction:
 
 ```sh
 error: variable name 'example' is undefined
-   in: example.glang:1:1
-   +
-   |
-   | example
-   | ^^^^^^^
-   |
-   + --> help: you can define a variable like 'obj my_variable = 1;'
-process finished with exit code -1
+    --> example.glang:1:1
+     |
+   1 | example
+     | ^^^^^^^ help: define a variable with the syntax 'obj <variable name> = <value>;'
+```
+
+Nice start, kdog — this already reads clearly and has a good flow! Let’s tighten it up a bit, make the explanation a little more structured, and highlight *why* the traceback happens so readers really “get” it.
+
+Here’s a refined version:
+
+---
+
+## Tracebacks
+
+Sometimes, multiple errors appear at once. This is called a **traceback**. A traceback happens when an error is **propagated upward** through the code, from where it occurs to wherever the function was called.
+
+For example, consider the `push` function:
+
+```
+push("", "");
 ```
+
+Here, both arguments are strings, but `push` expects the first argument to be a **list**. GLang first detects the problem inside its library code, then reports it again at the point where you called the function.
+
+That’s why you’ll see two errors:
+
+```sh
+error: argument 'list' must be type list
+    --> library/fundamental/list.glang:7:9
+     |
+   7 |         uhoh("argument 'list' must be type list");
+     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: argument 'list' must be type list
+    --> example.glang:1:1
+     |
+   1 | push("", "");
+     | ^^^^^^^^^^^
+```
+
+The first error shows **where** the problem started (inside the GLang library). The second shows **where** it reached the code.