:: ARITHM semantic presentation
theorem
Th1
:
:: ARITHM:1
for
x
being
complex
number
holds
x
+
0
=
x
proof
end;
Lemma18
:
-
0
=
0
proof
end;
Lemma19
:
opp
0
=
0
proof
end;
theorem
Th2
:
:: ARITHM:2
for
x
being
complex
number
holds
x
*
0
=
0
proof
end;
theorem
Th3
:
:: ARITHM:3
for
x
being
complex
number
holds 1
*
x
=
x
proof
end;
theorem
Th4
:
:: ARITHM:4
for
x
being
complex
number
holds
x
-
0
=
x
proof
end;
theorem
Th5
:
:: ARITHM:5
for
x
being
complex
number
holds 0
/
x
=
0
proof
end;
Lemma22
: 1
"
=
1
proof
end;
theorem
Th6
:
:: ARITHM:6
for
x
being
complex
number
holds
x
/
1
=
x
proof
end;