This is my very first day using Mathematica, so please forgive me my complete ignorance...

I fear that this might be one of those questions that gets rejected for being "easily found in the documentation"... 
Nevertheless, searching hard and long through the documentation all that I may, I completely fail to find an answer to my - no doubt obvious - mistake...

I tried to define a function x[t_] and a function y[t_], both as it seems successfully...

I then tried to put them together in a complex valued function f[t_], which I believed to be an operation that could not possibly go wrong... 

However to my surprise I keep getting a "Recursion depth of 1024 exceeded during evaluation of f[0]" error...

I really fail to see where this "recursion" could possibly come from...

Could anyone please put this noobie on the right track?

a = 2
(* 2 *)

T = 2^(3/2)
(* 2 Sqrt[2] *)

x[t_] = a Cos[2 Pi t/T] - Cos[2 Pi t]
(* -Cos[2 \[Pi] t] + 2 Cos[(\[Pi] t)/Sqrt[2]] *)

y[t_] = a Sin[2 Pi t/T] - Sin[2 Pi t]
(* -Sin[2 \[Pi] t] + 2 Sin[(\[Pi] t)/Sqrt[2]] *)

f[t_] = x[t] + I y[t]

During evaluation of In[112]:= $RecursionLimit::reclim2: Recursion depth of 1024 exceeded during evaluation of f[0]. &gt;&gt;
During evaluation of In[112]:= Set::write: Tag Hold in Hold[f[0]] is Protected. &gt;&gt;

(* -Cos[2 \[Pi] t] + 2 Cos[(\[Pi] t)/Sqrt[2]] + 
    I (-Sin[2 \[Pi] t] + 2 Sin[(\[Pi] t)/Sqrt[2]]) *)

f[0]

During evaluation of In[113]:= $RecursionLimit::reclim2: Recursion depth of 1024 exceeded during evaluation of f[0]. &gt;&gt;

(* Hold[f[0]] *)



Question: Does "so far, so good" carry a negative connotation?
Answer: I'd say it was neutral rather than negative. It means something like Everything's OK so far. Let's hope it stays that way.