LessEqual a <= b returns True if a is less than or equal to b. Attributes[LessEqual] := {Protected} Simple examples In[1]:= (a) <= (b) Out[1]= (a) <= (b) In[2]:= (1) <= (2) Out[2]= True In[3]:= (3) <= (5.5) Out[3]= True In[4]:= (5.5) <= (3) Out[4]= False In[5]:= (3) <= (3) Out[5]= True In[6]:= (1) <= (2) <= (3) Out[6]= True