From 873361af732757ae8e1feb5e625d38d032b4c482 Mon Sep 17 00:00:00 2001
From: kalmarek <kalmar@amu.edu.pl>
Date: Wed, 7 Oct 2020 02:33:58 +0200
Subject: [PATCH] allow numbers > 9 in subscriptify

---
 src/AutGroup.jl | 25 +++++++++++++++----------
 1 file changed, 15 insertions(+), 10 deletions(-)

diff --git a/src/AutGroup.jl b/src/AutGroup.jl
index fa05877..6e373af 100644
--- a/src/AutGroup.jl
+++ b/src/AutGroup.jl
@@ -35,9 +35,7 @@ end
 # https://github.com/JuliaIntervals/ValidatedNumerics.jl/blob/master/LICENSE.md
 function subscriptify(n::Integer)
     subscript_0 = Int(0x2080) # Char(0x2080) -> subscript 0
-    @assert 0 <= n <= 9
-    return Char(subscript_0 + n)
-    # return [Char(subscript_0 + i) for i in reverse(digits(n))])
+    return join([Char(subscript_0 + i) for i in reverse(digits(n))], "")
 end
 
 function id_autsymbol()
@@ -45,18 +43,26 @@ function id_autsymbol()
 end
 
 function transvection_R(i::Integer, j::Integer, pow::Integer=1)
-    id = Symbol("ϱ", subscriptify(i), subscriptify(j))
+    if 0 < i < 10 && 0 < j < 10
+        id = Symbol(:ϱ, subscriptify(i), subscriptify(j))
+    else
+        id = Symbol(:ϱ, subscriptify(i), "." ,subscriptify(j))
+    end
     return AutSymbol(id, pow, RTransvect(i, j))
 end
 
 function transvection_L(i::Integer, j::Integer, pow::Integer=1)
-    id = Symbol("λ", subscriptify(i), subscriptify(j))
+    if 0 < i < 10 && 0 < j < 10
+        id = Symbol(:λ, subscriptify(i), subscriptify(j))
+    else
+        id = Symbol(:λ, subscriptify(i), "." ,subscriptify(j))
+    end
     return AutSymbol(id, pow, LTransvect(i, j))
 end
 
 function flip(i::Integer, pow::Integer=1)
     iseven(pow) && return id_autsymbol()
-    id = Symbol("ɛ", subscriptify(i))
+    id = Symbol(:ɛ, subscriptify(i))
     return AutSymbol(id, 1, FlipAut(i))
 end
 
@@ -66,7 +72,7 @@ function AutSymbol(p::Generic.Perm, pow::Integer=1)
     end
 
     if any(p.d[i] != i for i in eachindex(p.d))
-        id = Symbol("σ", "₍", [subscriptify(i) for i in p.d]..., "₎")
+        id = Symbol(:σ, "₍", join([subscriptify(i) for i in p.d],""), "₎")
         return AutSymbol(id, 1, PermAut(p))
     end
     return id_autsymbol()
@@ -78,9 +84,8 @@ end
 σ(v::Generic.Perm, pow::Integer=1) = AutSymbol(v, pow)
 
 function change_pow(s::AutSymbol, n::Integer)
-    if n == zero(n)
-        return id_autsymbol()
-    end
+    iszero(n) && id_autsymbol()
+
     symbol = s.fn
     if symbol isa FlipAut
         return flip(symbol.i, n)