### Is there a way in sagemath's BooleanPolynomialRing Change the value in the boolean function through the variable in the list

~~when ~~When we ~~can not ~~cannot determine which variable will be ~~determine ~~determined by a ~~constant，i use a list ~~constant,
I use a list to store ~~variables ,but ~~variables, but the ~~BooleanPolynomialRing do not ~~`BooleanPolynomialRing`

does not
support change the ~~BooleanPolynomial ~~`BooleanPolynomial`

by variables in ~~list, ~~list.

It seems that it can only be changed by using the variable ~~name; ~~name;
but when we encounter this ~~situation ,is ~~situation, is there another ~~way ~~way
to solve this ~~problem
```
~~problem?

```
sage: from sage.crypto.boolean_function import BooleanFunction
```~~R=BooleanPolynomialRing(4,"a,b,c,d")~~sage: R = BooleanPolynomialRing(4, "a, b, c, d")
sage: R.inject_variables()
Defining a, b, c, d
sage: S = R.gens()
sage: print(S)
(a, b, c, d)
R.inject_variables()

sage: f = a*b + b*c
sage: print(f(a=1))
b*c + b
~~ ~~S=R.gens()
print(S)
f=a*b+b*c

print(f(a=1))

sage: print(f(S[0]=1))
~~```~~

File "<ipython-input-9-504c2572fec0>", line 1
print(f(S[Integer(0)]=Integer(1)))
^
SyntaxError: expression cannot contain assignment, perhaps you meant "=="?