* HOL/List: new function list_update written xs[i:=v] that updates the i-th
list position. May also be iterated as in xs[i:=a,j:=b,...].
LP = Base +
rules
pi_sb "[| A:*; !!x. x:A ==> B(x):[] |] ==> Prod(A,B):[]"
lam_sb "[| A:*; !!x. x:A ==> f(x):B(x); !!x. x:A ==> B(x):[] |]
==> Abs(A,f) : Prod(A,B)"
end