比較演算子と算術演算子

昨日の件ですが。
懲りずに引き続き基本的な部分を確認（別名、忙しくて時間を取れなかったとも言う）。

% /usr/bin/erl
Erlang (BEAM) emulator version 5.5.2 [source] [async-threads:0] [kernel-poll:false]

Eshell V5.5.2  (abort with ^G)
1> 1   ==  1.
true
2> 1   ==  2.
false
3> 1   ==  1.0.
true
4> 1   =:= 1.0.
false
5> 1   ==  "1".
false
6> "1" =:= "1".
true
7> 1   =/= 1.
false
8> 1   =/= 1.0.
true
9> 1   =/= "1".
true
10> "1" =/= "1".
false
11> 1   /=  1.
false
12> 1   /=  1.0.
false
13> 1   /=  "1".
true
14> 1   /=  2.
true
15> 1   <   2.
true
16> 2   <   2.0.
false
17> 1   >   2.
false
18> 1   >   1.0.
false
19> 1   =<  2.
true
20> 1   =<  1.0.
true
21> 1   >=  1.
true
22> 1   >=  1.0.
true
23> 1   + 1.
2
24> 1   + "1".

=ERROR REPORT==== 15-May-2007::22:14:10 ===
Error in process <0.30.0> with exit value: {badarith,[{erl_eval,eval_op,3},{shell,exprs,6},{shell,eval_loop,3}]}

** exited: {badarith,[{erl_eval,eval_op,3},
                      {shell,exprs,6},
                      {shell,eval_loop,3}]} **
25> 1   + 1.0.
2.00000
26> 0   - 1.
-1
27> 0   - 1.0.
-1.00000
28> 1   - 1.
0
29> 1   - "1".

=ERROR REPORT==== 15-May-2007::22:14:30 ===
Error in process <0.55.0> with exit value: {badarith,[{erl_eval,eval_op,3},{shell,exprs,6},{shell,eval_loop,3}]}

** exited: {badarith,[{erl_eval,eval_op,3},
                      {shell,exprs,6},
                      {shell,eval_loop,3}]} **
30> 1   - 1.0.
0.00000e+0
31> 2   * 2.
4
32> 2   * 2.0.
4.00000
33> 2   / 2.
1.00000
34> 2   / 2.0.
1.00000
35> 2   / 10.
0.200000
36> 3   div 0.

=ERROR REPORT==== 15-May-2007::22:15:01 ===
Error in process <0.61.0> with exit value: {badarith,[{erl_eval,eval_op,3},{shell,exprs,6},{shell,eval_loop,3}]}

** exited: {badarith,[{erl_eval,eval_op,3},
                      {shell,exprs,6},
                      {shell,eval_loop,3}]} **
37> 3   div 1.
3
38> 3   div 2.
1
39> 3   div 3.
1
40> 3   div 3.0.

=ERROR REPORT==== 15-May-2007::22:15:07 ===
Error in process <0.69.0> with exit value: {badarith,[{erl_eval,eval_op,3},{shell,exprs,6},{shell,eval_loop,3}]}

** exited: {badarith,[{erl_eval,eval_op,3},
                      {shell,exprs,6},
                      {shell,eval_loop,3}]} **
41> 3.0 div 3.

=ERROR REPORT==== 15-May-2007::22:15:09 ===
Error in process <0.74.0> with exit value: {badarith,[{erl_eval,eval_op,3},{shell,exprs,6},{shell,eval_loop,3}]}

** exited: {badarith,[{erl_eval,eval_op,3},
                      {shell,exprs,6},
                      {shell,eval_loop,3}]} **
42> 3.0 div 3.0.

=ERROR REPORT==== 15-May-2007::22:15:14 ===
Error in process <0.76.0> with exit value: {badarith,[{erl_eval,eval_op,3},{shell,exprs,6},{shell,eval_loop,3}]}

** exited: {badarith,[{erl_eval,eval_op,3},
                      {shell,exprs,6},
                      {shell,eval_loop,3}]} **
43> 3   div "3".

=ERROR REPORT==== 15-May-2007::22:15:28 ===
Error in process <0.78.0> with exit value: {badarith,[{erl_eval,eval_op,3},{shell,exprs,6},{shell,eval_loop,3}]}

** exited: {badarith,[{erl_eval,eval_op,3},
                      {shell,exprs,6},
                      {shell,eval_loop,3}]} **
44> 3   div 4.
0
45> 3   rem 0.

=ERROR REPORT==== 15-May-2007::22:15:31 ===
Error in process <0.80.0> with exit value: {badarith,[{erl_eval,eval_op,3},{shell,exprs,6},{shell,eval_loop,3}]}

** exited: {badarith,[{erl_eval,eval_op,3},
                      {shell,exprs,6},
                      {shell,eval_loop,3}]} **
46> 3   rem 1.
0
47> 3   rem 2.
1
48> 3   rem 3.
0
49> 3   rem 3.0.

=ERROR REPORT==== 15-May-2007::22:15:36 ===
Error in process <0.83.0> with exit value: {badarith,[{erl_eval,eval_op,3},{shell,exprs,6},{shell,eval_loop,3}]}

** exited: {badarith,[{erl_eval,eval_op,3},
                      {shell,exprs,6},
                      {shell,eval_loop,3}]} **
50> 3.0 rem 3.

=ERROR REPORT==== 15-May-2007::22:15:49 ===
Error in process <0.88.0> with exit value: {badarith,[{erl_eval,eval_op,3},{shell,exprs,6},{shell,eval_loop,3}]}

** exited: {badarith,[{erl_eval,eval_op,3},
                      {shell,exprs,6},
                      {shell,eval_loop,3}]} **
51> 3.0 rem 3.0.

=ERROR REPORT==== 15-May-2007::22:15:53 ===
Error in process <0.90.0> with exit value: {badarith,[{erl_eval,eval_op,3},{shell,exprs,6},{shell,eval_loop,3}]}

** exited: {badarith,[{erl_eval,eval_op,3},
                      {shell,exprs,6},
                      {shell,eval_loop,3}]} **
52> 3   rem "3".

=ERROR REPORT==== 15-May-2007::22:15:54 ===
Error in process <0.92.0> with exit value: {badarith,[{erl_eval,eval_op,3},{shell,exprs,6},{shell,eval_loop,3}]}

** exited: {badarith,[{erl_eval,eval_op,3},
                      {shell,exprs,6},
                      {shell,eval_loop,3}]} **
53> 3   rem 4.
3

「=<」とか「/=」は絶対間違えそう。。。っていうか、演算子が特殊スギル。
時間が無いので今日はココまで。もう少し余裕が出てくれば良いのですが、先は長そう。＿|￣|○