Not a problem in practice., but good to fix anyway.

---------------------------------
module foo
strategies

  main =
    foo

  external foo(|t)
---------------------------------

---------------------------------
[ strc | info ] Front-end succeeded : [user/system] = [0.33s/0.53s]
[ strc | info ] Optimization succeeded -O 2 : [user/system] = [0.01s/0.05s]
[ strc | info ] Back-end succeeded : [user/system] = [0.14s/0.14s]
[ strc | error ] Command failed :
foo.c:15: error: redefinition of parameter 't'
foo.c:15: error: previous definition of 't' was here
foo.c: In function `main_0_0':
foo.c:18: error: too few arguments to function `foo_0_1'
---------------------------------

C header:
---------------------------------
ATerm foo_0_1 (ATerm t, ATerm t);
---------------------------------