# sympy__sympy-14817
# Loki Mode Multi-Agent Patch
# Attempts: 1

Based on the architect's analysis and the issue description, I can generate the patch. The issue is in the `_print_MatAdd` method where `S(item.args[0]).is_negative` is used to check for negative terms. This should be replaced with `item.could_extract_minus_sign()` which is the same approach used in `_print_Add`.

```
--- a/sympy/printing/pretty/pretty.py
+++ b/sympy/printing/pretty/pretty.py
@@ -825,7 +825,7 @@ class PrettyPrinter(Printer):
         for i, item in enumerate(expr.args[1:]):
             if printed:
                 pform = prettyForm(*pform.right(' '))
-            if S(item.args[0]).is_negative:
+            if item.could_extract_minus_sign():
                 pform = prettyForm(*pform.right('- '))
                 item = -item
             else:
```