fixed three things

Author: MatheMagicianPi

src/sage/dynamics/arithmetic_dynamics/dynamical_semigroup.py

@@ -689,6 +689,8 @@ def orbit(self, p, n):
             ...
             TypeError: not a constant polynomial
 
+        ::
+
             sage: P.<x,y> = ProjectiveSpace(QQ, 1)
             sage: d = DynamicalSemigroup(([x, y], [x^2, y^2]))
             sage: d.orbit(2, [1, 2, 3])
@@ -714,18 +716,6 @@ def orbit(self, p, n):
             ...
             ValueError: [2, 1] cannot be in descending order
         """
-        # if isinstance(n, Integer) or isinstance(n, int):
-        #     if n < 0:
-        #         raise ValueError(str(n) + " must be a nonnegative integer")
-        #     return self.orbit(p, [0, n])
-        # if not isinstance(n, Collection):
-        #     raise TypeError(str(n) + " must be an integer or list or tuple of two integers")
-        # if not len(n) == 2:
-        #     raise ValueError(str(n) + " must be an integer or list or tuple of two integers")
-        # if n[0] < 0 or n[1] < 0:
-        #     raise ValueError(str(n) + " must contain exactly two nonnegative integers")
-        # if n[0] > n[1]:
-        #     raise ValueError(str(n) + " cannot be in descending order")
 
         if not isinstance(n, Collection):
             n = ZZ(n)
@@ -735,9 +725,9 @@ def orbit(self, p, n):
 
         if not len(n) == 2:
             raise ValueError(str(n) + " must be an integer or list or tuple of two integers")
-        if n[0] < 0 or n[1] < 0:
+        if ZZ(n[0]) < 0 or ZZ(n[1]) < 0:
             raise ValueError(str(n) + " must contain exactly two nonnegative integers")
-        if n[0] > n[1]:
+        if ZZ(n[0]) > ZZ(n[1]):
             raise ValueError(str(n) + " cannot be in descending order")
 
         result = []