In[1]:= Simplify[x<0, x<0] Out[1]= True In[2]:= Simplify[x<0, {x,y}<0] Out[2]= x < 0 In[3]:= $ Version Out[3]= 11.1.0 for Linux x86 (64-bit) (March 13, 2017) I always thought {x,y}<0 meant the same thing as {x<0, y<0}, but, per In[2] above, this doesn’t appear to be the case. Does {x,y}<0 have a useful meaning or am IRead more