str2tex done and integrate into MO

mapytex/calculus/core/MO/mo.py

@@ -7,7 +7,7 @@
 # Distributed under terms of the MIT license.
 
 from ..coroutine import coroutine, STOOOP
-from ..renders import tree2txt
+from ..renders import tree2txt, tree2tex
 from decimal import Decimal
 
 
@@ -91,6 +91,13 @@ class MO(object):
         except AttributeError:
             return str(self.value)
 
+    @property
+    def __tex__(self):
+        try:
+            return tree2tex(self.value)
+        except AttributeError:
+            return str(self.value)
+
     def __add__(self, other):
         """ Overload + for MOs
 
@@ -195,6 +202,12 @@ class MOnumber(MO):
 
         return f"- {abs(self.value)}"
 
+    @property
+    def __tex__(self):
+        if self.value > 0:
+            return str(self.value)
+
+        return f"- {abs(self.value)}"
         
 class MOstr(MO):