let f, g be Function of (product (carr G)),REAL; :: thesis: ( ( for x being Element of product (carr G) holds f . x = |.(normsequence (G,x)).| ) & ( for x being Element of product (carr G) holds g . x = |.(normsequence (G,x)).| ) implies f = g )
assume that
A2: for x being Element of product (carr G) holds f . x = |.(normsequence (G,x)).| and
A3: for x being Element of product (carr G) holds g . x = |.(normsequence (G,x)).| ; :: thesis: f = g
now :: thesis: for x being Element of product (carr G) holds f . x = g . x
let x be Element of product (carr G); :: thesis: f . x = g . x
f . x = |.(normsequence (G,x)).| by A2;
hence f . x = g . x by A3; :: thesis: verum
end;
hence f = g by FUNCT_2:63; :: thesis: verum