Constant is an attribute that indicates zero derivative of a symbol with respect to all parameters.

π is a mathematical constant representing a number: In[1]:=Attributes[π] Out[1]={Constant, Protected, ReadProtected} π is not explicitly a number: In[2]:=NumberQ[π] Out[2]=False π is numeric and evaluates to a number with N: In[3]:=NumericQ[π] Out[3]=True In[4]:=N[π, 32] Out[4]=3.1415926535897932384626433832795 Define f to be a constant function for total derivatives computed with Dt: In[1]:=SetAttributes[f, Constant] In[2]:=Dt[g[x, y] f[x, y]] Out[2]=f[x, y] (Dt[y] g^(0, 1)[x, y] + Dt[x] g^(1, 0)[x, y])

Protected

Constants

1704th most common (1 in 350000 symbols)

3774th most common (1 in 215000 symbols)

introduced in Version 1 (June 1988)