|
数学专业英语-(a) How to define a mathematical term?
, {) Z# C1 s5 L! y6 R' P! `" O% P
1 P" N% @0 }5 n! J % j& q; a/ v) D: ?: l" `6 ~6 ^$ k
$ J2 W5 t6 D3 ?8 d
2 g! I% k* o6 h2 m: k) U 数学术语的定义和数学定理的叙述,其基本格式可归纳为似“if…then…”的格式,其他的格式一般地说可视为这一格式的延伸或变形。 % W+ v% R. e# V4 g6 o
, _6 G( j4 Y6 c" Q" i" h3 ?8 K C
7 B' R- K1 ^. Y! k# \
7 h/ ^3 h0 g( e. D, o 如果一定语短语或定语从句,以界定被定义的词,所得定义表面上看虽不是“If……then……”的句型,而实际上是用“定语部分”代替了“If”句,因此我们可以把“定语部分”写成If句,从而又回到“If……then……”的句型。 ; A) o! `, K8 |+ B C. m' b
2 ]: M, r2 ~- G$ s& \8 s
, ]% N3 }- _# J: h" ? 至于下面将要叙述的“Let…if…then”,“Let and assume…, If…then…”等句型,其实质也是基本句型“If……then……”的延伸。
2 A. ~8 `- l) I' E- K, Y8 s" K # |! [4 e1 ?6 ~/ }$ i: j* x
! a* H2 H% T0 d6 w9 Y- x 有时,在定义或定理中,需要附加说明某些成份,我们还可在“if…then…”句中插入如“where…”等的句子,加以延伸(见后面例子)。
. l5 T5 t" Q1 R" I- W 1 d9 M, U( D3 R, F8 {1 K
+ Y W, `. x" \ 总之,绝大部分(如果不是全部的话)数学术语的定义和定理的叙述均可采用本附录中各种格式之。 8 U( X% m3 d* T5 \
/ w' ]1 F0 U: a; N
' B1 R3 x# c' H4 U
; B" b; c; u$ v- C2 U! J6 _2 U; O ?( V6 C$ E9 w
`4 K6 \/ R& f
, @0 @5 ?, Z& v* m% b4 n/ v, F( m8 K+ e c! j; S: u8 N: y
0 ]. e2 v& s' U- e/ C2 n (a)How to define a mathematical term?$ }5 d f, h8 }, r
' l% W; w/ o5 g- F' ^% r& r. j8 l
& h1 ~8 C) u, x9 O$ S) c
2 F) U0 U2 N! E' |2 W
! [/ b: O0 _- t( H1 M: f1 ^1 x7 H1 [8 w
\$ W- A0 C. h. }- c- l8 V|
, b# U6 v" N: J6 d is defined as
5 Y" ^6 S( r* d( g3 z; Q
p- R' e9 x, {; a- e) W' v3 }1 t9 S
/ f& U/ e2 c- S7 _* m is called
; G. v9 w& a6 [+ ?1 x, i! P: y% I3 [- K& u& h% Z/ V; s0 C
| 1 O3 H R$ x; T8 {, ~0 z2 k/ }
1. Something something ! P0 B" h+ f# z& M. P2 ~
0 K, X5 b/ E5 }+ c
8 u4 W9 A! [: J S
0 \! k" r2 t' ~6 ^& G2 M% p
1 k" Q n7 u5 N- S
" g$ Z. D1 Q% t* c) s9 w
/ W* ~) j$ R2 T& U) z, j& ?/ }- A# x/ j) T+ G' ]4 R+ ^0 n6 M8 c) J
5 w! s1 ^' _: j
The union of A and B is defined as the set of those elements which are in A, in B or in both. 4 x/ @' Z) ^- h; d- T* |. m
/ J% ~- e) j% {3 }8 U" e
0 a8 O& [' V" m& W( J, j! j2 a The mapping , ad-bc 0, is called a Mobius transformation. " p8 N4 z* O+ r, @1 g3 F0 ~) R
/ v2 N& y7 O8 r! a( l
2 r" V5 u& ?7 }. ?! c ) w3 L2 g8 X, h# v
1 [6 _4 c; @- f; K
% v3 M! v; ]2 W& E) @* S, U
|
3 n; @4 |& A6 K( [ is defined to be 2 Y( N }- K" L( [* T+ _- H
5 z' h% r' I0 R; v 6 ~' C4 N. n& L8 u' p# X+ N
is said to be
: n# {. L0 _- E
/ Z7 y( p& ]: H9 N8 W3 k |
x! [* o- X9 y- x- S6 L# F; [2. Something something(or adjective)
* y( k3 [( r' D9 X% n9 a: L$ ^0 }: [- w4 X
% F' G. x) ?4 V& W4 }
, @/ u7 Q- d$ ?- u
x* { D' E3 G% Q+ D# ^4 i
- ]% G1 c3 A% M
* E. W* r4 z+ E' t* b
2 ~) H2 V2 W0 w & O" ?6 \ h# k1 J) M# T: s
The difference A-B is defined to be the set of all elements of A which are not in B. , K! |1 O. E: s( S$ N
' [" w3 u1 B3 V: |: o
# c/ a0 F8 i8 c A real number that cannot be expressed as the ratio of two integers is said to be an irrational number.
. X" A- i( N2 w
, N* z5 t: y7 I8 s$ d0 F0 W5 Y , l5 @, l( W4 W+ S
Real numbers which are greater than zero are said to be positive. 2 c% J0 S# B) ]! n
( K4 o5 \( b" Q. F* h0 W
! u# S& {- F: O. s1 X, x 8 i' `9 ?; ^4 r9 j' j8 q: b
' j# q" @. P+ H
- z1 |* l$ P- M( q7 H. p, n1 x| 7 R" K1 W$ x& ~
define 8 f) Z8 b8 g5 j% Y8 {
2 K! i9 k/ g. P- H/ V% K* q: h& t+ V+ A
' s1 _$ ~, h# Z/ Z1 I( ~' M! X6 U call
7 n* `: s# @( C& N( \
0 U8 w' ~! w& h2 I' y/ H1 h | + k: S( W3 e* l4 D! O. O# g$ z
3. We something to be something. $ J6 t" ^& ` V7 l9 x7 d
* b& r# |, | p+ w
8 i0 J3 N6 F) l , ^/ S' A T: C# N5 R* F2 [( b* h
5 q- ~3 y4 V4 U0 R: R3 }% V
% B+ r: P3 p ?* L 4 o9 A/ G! q. i% ]" x
/ V/ y$ ]# ]+ o/ G " }* i; O, {* q* b
We define the intersection of A and B to be the set of those elements common to both A and B. 6 y/ M! W, \0 C7 I9 V8 \* ^3 K( W
9 \/ C7 J2 p- A1 Z l) s , M: E% j% ^$ w3 H* b8 Q& u6 G
We call real numbers that are less than zero (to be) negative numbers. 0 i8 I0 E" {7 ` o% H' B* p# y3 q
4 D' C3 Q1 J/ q6 y# F5 J' u7 v7 Y C
/ y, c4 Y0 t. u1 D u. ^5 M3 Y- R 4. 如果在定义某一术语之前,需要事先交代某些东西(前提),可用如下形式: ( h T* N( c5 u
Q) n3 _. i& I6 ^, U U. j4 ^$ n
) F3 P0 V. O4 R/ U
# Y+ c, @" d8 @4 w; D
. q, s3 P9 b5 Q7 d% K( _4 [
$ R/ Y/ U% Z. p 7 M& p" [, C1 U; k! l8 @
6 F0 w, M& K9 Q. l0 W/ P2 y- z
( h2 k, q( A% B! L) d: t* z( l
5 R- j; I' f& o+ w
/ N1 b, `) N c( O, @' I& ]& f3 Q3 G2 p1 K5 k+ Z
| - u2 W; s" D: U1 O# N& B: }- F& J
is called
" @* O" C& U2 r, s7 c+ u2 W( c6 u: c9 i% k
6 T2 g3 h. X" o, c2 O
is said to be ) c5 @3 T* c+ d
$ U, r% i- T4 @5 q$ S+ S0 {
) l$ ~" [# {7 y& u" v) ^; @
is defined as # m! U: g. s' |8 N
6 \% g* K4 m" m; e. ~* s
; i8 t& A+ [- P4 [0 H6 L1 J
is defined to be 7 M! o- w$ [ T4 W7 w
& f, t H& ?2 m9 Z
| + ]1 q: T# w T( _* G% T
Let…, then…
+ {$ r. v6 i8 ]! S7 v) t Y6 p6 }! \/ j7 h. d1 q
0 g( R( }5 I0 K1 I. b
# D) L% P' k0 w
3 k7 N O# F% Z* g
8 {4 y+ y. ] p: ~, o
+ k8 b; V0 {8 }
6 x) J7 U% u5 g. o; |
; o7 _# I2 T4 d @2 F
1 ?( x% Q2 B6 U* w( {$ @' L0 E% f$ B8 b
, d2 \8 R4 H; V$ a+ s* z: o$ U3 k 3 F i) I/ w, I. V5 }
* C$ A2 D" G3 g; u& L1 I& { " _- D; E; C( h' Z% z
Let x=( ) be an n-tuple of real numbers. Then the set of all such n-tuples is defined as the Euclidean n-space R. % j- k9 A/ {6 {. ^- t T
+ f. n* G0 y: \" v
4 _+ `% w8 G7 S/ `& x9 c Let d(x,y) denote the distance between two points x and y of a set A. Then the number + v8 K s3 G: k& e
& a0 U" h$ Y) i3 O) q! ?
) Y7 h5 v: J) e5 A
D= / ?5 |3 q% p# \/ X2 `
+ v5 I( H- Z* }( L2 `+ R, q4 H
& f6 O6 ^; \4 f l is called the diameter of A.
& D: P/ T- r( F
) @& S+ p* P: _" c , r% P, I! f5 K# N3 m. T
5.如果被定义术语,需要满足某些条件,则可用如下形式: $ A ~+ v& H0 ]" Y% ~5 y
' j3 n; P9 B. f/ m4 \4 G. J & u' @1 d& Z4 u2 g% `8 ]- H3 }! g
( L/ B% @+ H) Z+ P& I& H& P1 F
/ e @( C0 q+ y1 w+ W: v$ q
# Z7 i; w* }- K* x3 ?|
- B5 m" I" k0 [/ c is called ; s5 h. }- u' j( C. x! a( J4 i
+ P( Q, I* L7 K) V9 l- ]5 G {9 {/ O
6 b* n( t' d9 h' c% s! x
is said to be . U, n I! C: ]$ W% O r# Q* @
) Y9 `2 F4 s# p) l, l
5 u. S" }/ B6 w" R$ c. A5 n
is defined as
# O v' N, {2 V C x& L1 @
* h2 s+ T0 T4 _; N' Y! W0 Y ) O4 g# h) B. ?& d) Y4 T1 o3 v7 Q/ A
is defined to be & G7 [ i3 N; e5 Q( M H
4 ^" u! v- ~# T) Q* t: p# Y/ f9 O | ; v. m, P3 b: b# N9 F
If…, then… / O0 G& S5 Q) e# ^
! l" }+ W+ {- C
4 y k7 _9 k4 \- w0 z
( j' r; h1 b+ i) ^8 B9 f
9 z! b: Z* Z3 Y8 r$ g9 P [( m2 } ( K: d1 Z3 n! @
" R2 S( a* u$ K1 B: p: h
+ Q- ]5 s+ `% ?0 W( y
& f/ V5 j3 E) h , L$ |$ [% G2 B" U+ g/ c$ x+ }
( X, s% F; j+ C: v/ z% `9 R" B
1 |* l) c Z4 `* k4 ^ 7 F- ]( L0 g6 `, @5 J M
5 Y" D% {* W! O $ O s1 j" r# Z8 D
If the number of rows of a matrix A equals the number of its columns, then A is called a square matrix.
; m* a' b% R+ N# h" P+ D$ ^5 Z
+ {% x# Y! J: S% _- f7 p: X/ l + L2 T$ _9 T8 S7 L3 Q
If a function f is differentiable at every point of a domain D, then it is said to be analytic in D. & h3 S( ]( o) A K# q; M
8 W: h* b: h) U" ]5 Q9 n; _ 2 r' S$ C8 M" \! W2 \; L
6.如果需要说明被定义术语应在什么前提下,满足什么条件,则可用下面形式: 6 r b( u# T h0 d. \- j. r
* x" K. K8 U% X, H& C
! B9 [/ W2 c& T
' H# b1 @/ `* l3 C
/ V& Z6 p$ T7 X/ G, e4 D6 b+ D* ^& Y8 v' N' t2 _2 p- ?& |
! I2 u0 k2 Z( M, Q9 ]2 f! ~# P% H0 @. S: E. N8 m
" Y7 j( x, k P% N$ ^% s( t5 N7 gis called
! P i& w6 E$ T6 w/ O- t! y/ nis said to be | / A: P( f# \4 r1 w
! A4 [/ s& g q* i: o$ z0 E1 u# Y, F4 q! A- l" U. Q( i
! [/ E* q3 }) n* g& A. i; Z: j! @4 s
I }; B3 J6 [. z
Let
* p1 h0 y) G4 {' O% Z% @: g- vSuppose | …. If…then… … 9 l ^# ^ h2 B
0 T. Q" `& d% f5 a( u. Y$ Y; Q
- i% Y$ W6 N/ U, r1 D& }! O1 p1 @! u. H8 u
3 y! |4 k2 e1 k& W' N# J9 D& K* j! Z( K8 y& X1 D! b' o
: b- ?; O6 w* Y4 _/ A4 R s9 C6 i: d! w4 P6 V
% w8 @- a6 Z- } h3 K6 V4 e
, \: g8 \6 X# g2 l' j Let f(z) be an analytic function defined on a domain D (前提条件). If for every pair or points , and in D with , we have f( ) f( ) (直接条件),then f(z) is called a schlicht function or is said to be schlicht in D. * ]- | X4 h7 l0 u; M' w# b
- w7 g8 k$ B i% U: y/ F% B
9 \$ r" A2 \4 b7 v3 }* e + _; _5 ]/ q! @/ s5 {1 q2 F+ Y
+ R( J- f; e9 F+ |" @8 t
|