From 508a006dc3998a144aae0e87f1ad130c5efde1dc Mon Sep 17 00:00:00 2001 From: szdytom Date: Mon, 7 Jul 2025 20:30:10 +0800 Subject: [PATCH] fix format Signed-off-by: szdytom --- sections/1B.typ | 30 +++++++++++++++--------------- 1 file changed, 15 insertions(+), 15 deletions(-) diff --git a/sections/1B.typ b/sections/1B.typ index b48b999..94f95f7 100644 --- a/sections/1B.typ +++ b/sections/1B.typ @@ -163,11 +163,11 @@ / 可结合性: 对于所有 $u_1,v_1,u_2,v_2,u_3,v_3 in V$,都有 $((u_1 + ii v_1) + (u_2 + ii v_2)) + (u_3 + ii v_3) = (u_1 + ii v_1) + ((u_2 + ii v_2) + (u_3 + ii v_3))$。 \ 证明:由加法的可结合性,$(u_1 + u_2) + u_3 = u_1 + (u_2 + u_3)$ 且 $(v_1 + v_2) + v_3 = v_1 + (v_2 + v_3)$,因此 - $ ((u_1 + ii v_1) + (u_2 + ii v_2)) + (u_3 + ii v_3) - &= ((u_1 + u_2) + ii (v_1 + v_2)) + (u_3 + ii v_3) \ - &= (u_1 + u_2 + u_3) + ii (v_1 + v_2 + v_3) \ - &= (u_1 + ii v_1) + ((u_2 + ii v_2) + (u_3 + ii v_3)) \ - &= (u_1 + ii v_1) + (u_2 + u_3) + ii (v_2 + v_3) $ + $ &((u_1 + ii v_1) + (u_2 + ii v_2)) + (u_3 + ii v_3) \ + =& ((u_1 + u_2) + ii (v_1 + v_2)) + (u_3 + ii v_3) \ + =& (u_1 + u_2 + u_3) + ii (v_1 + v_2 + v_3) \ + =& (u_1 + ii v_1) + ((u_2 + ii v_2) + (u_3 + ii v_3)) \ + =& (u_1 + ii v_1) + (u_2 + u_3) + ii (v_2 + v_3) $ / 加法单位元: 存在 $0 in complexification(V)$ 使得对于所有 $u,v in V$,都有 $(u + ii v) + 0 = u + ii v$。 \ 证明:取 $0 = 0 + ii 0$ 为 $complexification(V)$ 中的加法单位元。对于所有 $u,v in V$,都有 $ (u + ii v) + 0 = (u + ii v) + (0 + ii 0) \ @@ -185,17 +185,17 @@ = u + ii v $ / 分配性质: 对于所有 $u_1,v_1,u_2,v_2 in V$ 以及所有 $a,b in RR$,都有 $(a + b ii)((u_1 + ii v_1) + (u_2 + ii v_2)) = (a + b ii)(u_1 + ii v_1) + (a + b ii)(u_2 + ii v_2)$ 且 $(a + b ii)(u + ii v) = a(u + ii v) + b(u + ii v)$。 \ 证明:对于所有 $u_1,v_1,u_2,v_2 in V$ 和所有 $a,b in RR$,都有 - $ (a + b ii)((u_1 + ii v_1) + (u_2 + ii v_2)) - &= (a + b ii)((u_1 + u_2) + ii (v_1 + v_2)) \ - &= (a(u_1 + u_2) - b(v_1 + v_2)) + ii (a(v_1 + v_2) + b(u_1 + u_2)) \ - &= (a u_1 - b v_1) + ii (a v_1 + b u_1) + (a u_2 - b v_2) + ii (a v_2 + b u_2) \ - &= (a u_1 - b v_1 + a u_2 - b v_2) + ii (a v_1 + b u_1 + a v_2 + b u_2) \ - &= (a + b ii)(u_1 + ii v_1) + (a + b ii)(u_2 + ii v_2) $ + $ &(a + b ii)((u_1 + ii v_1) + (u_2 + ii v_2)) \ + =& (a + b ii)((u_1 + u_2) + ii (v_1 + v_2)) \ + =& (a(u_1 + u_2) - b(v_1 + v_2)) + ii (a(v_1 + v_2) + b(u_1 + u_2)) \ + =& (a u_1 - b v_1) + ii (a v_1 + b u_1) + (a u_2 - b v_2) + ii (a v_2 + b u_2) \ + =& (a u_1 - b v_1 + a u_2 - b v_2) + ii (a v_1 + b u_1 + a v_2 + b u_2) \ + =& (a + b ii)(u_1 + ii v_1) + (a + b ii)(u_2 + ii v_2) $ 另一方面,对于所有 $u,v in V$ 和所有 $a,b in RR$ - $ (a + b ii)(u + ii v) = (a u - b v) + ii (a v + b u) \ - = a(u + ii v) + b(u + ii v) \ - = (a u + a ii v) + (b u + b ii v) \ - = a(u + ii v) + b(u + ii v) $ + $ (a + b ii)(u + ii v) &= (a u - b v) + ii (a v + b u) \ + &= a(u + ii v) + b(u + ii v) \ + &= (a u + a ii v) + (b u + b ii v) \ + &= a(u + ii v) + b(u + ii v) $ #tab 综上所述,$complexification(V)$ 满足向量空间的所有要求,因此 $complexification(V)$ 是 $CC$ 上的向量空间。 ]