diff --git a/SAutFNs.jl b/groups/autfreegroup.jl
similarity index 95%
rename from SAutFNs.jl
rename to groups/autfreegroup.jl
index eac4f1f..717048b 100644
--- a/SAutFNs.jl
+++ b/groups/autfreegroup.jl
@@ -1,4 +1,4 @@
-module SAutFNs
+module SpecialAutomorphisms
 
 using Nemo
 using Groups
@@ -17,9 +17,8 @@ function generatingset(N::Int)
 
    SAutFN = AutGroup(FreeGroup(N), special=true)
    S = gens(SAutFN);
-   S = [S; [inv(s) for s in S]]
 
-   return SAutFN, unique(S)
+   return SAutFN, unique([S; inv.(S)])
 end
 
 function generatingset(parsed_args)
@@ -77,4 +76,4 @@ end
 
 groupname(N::Int) = "SAutF$(N)"
 
-end # of module SAutFNs
+end # of module SpecialAutomorphisms
diff --git a/SLNs.jl b/groups/speciallinear.jl
similarity index 97%
rename from SLNs.jl
rename to groups/speciallinear.jl
index 561ce45..1eb863e 100644
--- a/SLNs.jl
+++ b/groups/speciallinear.jl
@@ -1,4 +1,4 @@
-module SLNs
+module SpecialLinear
 
 using Nemo
 using Groups
@@ -21,6 +21,7 @@ function E(i::Int, j::Int, M::MatSpace, val=one(M.base_ring))
 end
 
 function SLsize(n,p)
+    p == 0 && return Inf
     result = BigInt(1)
     for k in 0:n-1
         result *= p^n - p^k
@@ -121,4 +122,4 @@ function groupname(N::Int, p::Int=0, X::Bool=false)
     return name
 end
 
-end # of module SLNs
+end # of module SpecialLinear