Fix(Render): Ajust "*" visibility with variables

mapytex/calculus/API/__init__.py

@@ -20,6 +20,7 @@ Generate and compute like a student!
 2 + 3 * 4
 2 + 12
 14
+
 >>> e = Expression.from_str("2+3/2")
 >>> e_simplified = e.simplify()
 >>> print(e_simplified)
@@ -32,6 +33,7 @@ Generate and compute like a student!
 4 / 2 + 3 / 2
 (4 + 3) / 2
 7 / 2
+
 >>> e = Expression.from_str("(2/3)^4")
 >>> e_simplified = e.simplify()
 >>> print(e_simplified)
@@ -41,6 +43,7 @@ Generate and compute like a student!
 (2 / 3)^4
 2^4 / 3^4
 16 / 81
+
 >>> e = Expression.from_str("x^2*x*x^4")
 >>> e_simplified = e.simplify()
 >>> print(e_simplified)

mapytex/calculus/core/renders/tree2tex.py

@@ -94,6 +94,8 @@ def mul2tex(left, right):
     >>> a = mo.MOstr('x')
     >>> mul2tex(mo.MO(3), a)
     '3x'
+    >>> mul2tex(a, a)
+    'x \\times x'
     """
     display_time = True
     try:
@@ -121,7 +123,7 @@ def mul2tex(left, right):
         else:
             right_ = tree2tex(right)
     finally:
-        if right_[0].isalpha():
+        if right_[0].isalpha() and (left_.isnumeric() or left_.isdecimal()):
             display_time = False
 
     if display_time:

mapytex/calculus/core/renders/tree2txt.py

@@ -94,6 +94,8 @@ def mul2txt(left, right):
     >>> a = mo.MOstr('x')
     >>> mul2txt(mo.MO(3), a)
     '3x'
+    >>> mul2txt(a, a)
+    'x * x'
     """
     display_time = True
     try:
@@ -121,7 +123,7 @@ def mul2txt(left, right):
         else:
             right_ = tree2txt(right)
     finally:
-        if right_[0].isalpha():
+        if right_[0].isalpha() and (left_.isnumeric() or left_.isdecimal()):
             display_time = False
 
     if display_time:

mapytex/calculus/core/typing/multiply.py

@@ -36,7 +36,7 @@ def moscalar_mostr(left, right):
     <MOMonomial 2x>
     >>> a = MOFraction(1, 5)
     >>> multiply(a, b)
-    <MOMonomial 1 / 5x>
+    <MOMonomial 1 / 5 * x>
     """
     return MOMonomial(left, right)
 
@@ -50,7 +50,7 @@ def mostr_moscalar(left, right):
     <MOMonomial 2x>
     >>> b = MOFraction(1, 5)
     >>> multiply(a, b)
-    <MOMonomial 1 / 5x>
+    <MOMonomial 1 / 5 * x>
     """
     return MOMonomial(right, left)