User talk:Hagman
Hello,
First of all I want to say that the definition of a "topology" rather than a Topological space is standard (ie Kelley General Topology) The definition is correct and you can easily prove it The notation (a)f instead of f(a) is standard too and, imo, it emphasises the formal idea of a function, so to say (a)f is to say a in pi_1(f) where f:=(A,f,B) so, for example, b=(a)f is to say (a,b) in f. i corrected and supress the use of the non-necessary symbols 1,2