|
数学专业英语-(a) How to define a mathematical term?
1 b0 v8 L9 h4 I/ w. x
+ k: a1 F' C" k
, e0 d7 G* f0 `3 `0 q' @
7 u0 a5 A9 |4 w# J7 q: c 3 x; J9 C+ b; O8 f6 D& f, Q
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。 " F' j& V: m" W
3 y2 D- ]: w3 }+ L
8 y5 D4 M) l$ g" v$ O
7 s- Y, e( |) d; C1 p. [
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。
7 J; |+ O; D2 l$ l" l( S8 @8 p: M & `6 V) |$ a$ W- I) w
- H# a& g6 V* _& P$ e 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。
5 z7 _! i# M6 g
1 n) E$ L9 [" h( o ( b/ c5 u3 y0 R$ M0 J
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)。
' {. h9 q) {5 s' j. G" s
4 _3 G/ r' g. y7 W" L2 h: d" o$ H 8 E! f k2 m0 V# B, S
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。 2 p% i) x5 F% F* F# X) H; T& ^
. s; X# c: h1 _" G# e% g [* E
; i; e2 _( k1 m6 T
5 b/ L5 r# U# N9 _, y2 ~4 E
, i) j- Z G$ w. Y! Y
7 o0 J/ M0 T) t f& v# u1 l \
+ U' t8 L8 N. H% |
' G3 c a! w$ @
# j1 G: `! \0 ~ (a)How to define a mathematical term?
, z' i i6 F6 x6 \4 U7 P$ E# N+ V, i" |" N6 m
5 K/ f8 O) h. C5 P* q8 r- b
# q$ t) C _/ ~1 p( j7 z + E# N1 Q" F* |2 z" w) H
) f! K3 ?; K. G7 H; g
. p+ [9 E( U; u! l- c
|
+ w0 q1 R5 K1 d: t( o6 F is defined as
/ B+ O! C- I) a8 p
: N/ r* U# u2 F$ I% C" J; W; t
8 c. X8 m! x& z* j% I4 F is called
# D" t! j" t7 U' S/ h7 Z) `+ ^3 i1 T5 l3 y; s8 z& @+ { o. h4 S
|
' h# @1 s9 a0 T) j1. Something something
) f4 D5 a9 o' R* g; Q: D% _6 v, G3 e$ o5 j X0 N; [
4 J9 q* r$ d: f) K+ m I9 Q4 y" T B$ L
; q- u& m% X$ A2 L! o6 Z4 w
, o1 ^) p: q. ~9 u$ L
# o1 t* M) E- j# p5 s# X( ?5 m$ ?! S( ]) w: j1 X
" ~2 A8 f7 E3 j& |% c% Y" t
The union of A and B is defined as the set of those elements which are in A, in B or in both. 9 [$ |+ l( F9 w9 @4 w- B
; H& H! R5 v A
+ f/ `6 W3 k2 y- ?& Q The mapping , ad-bc 0, is called a Mobius transformation. ( T; l' `! s; P
, u4 G, N4 U' i" J. a0 x
$ c: W% l0 t! I6 f) g7 ?
A4 `8 y+ o) J1 F1 p) j) q! p
0 W$ j# E2 t' }
$ ^) C' v1 b" W|
- u9 [( \$ ?2 ^/ r% K+ V' ` is defined to be 5 r0 ~6 ?! }1 y
8 ` `1 `0 s; f9 p5 [5 z, I
% o! Q/ _0 B6 h
is said to be # S f/ D9 a5 n' v% x( X' X
0 ]6 a% N7 W7 @" ?
| 2 m3 y, y c2 ~& }9 Z/ g
2. Something something(or adjective) 7 B0 u7 _: t4 Y! c7 L9 ~: G
! ?- i' {( X$ g2 p% F3 W7 [' l
8 x7 L# i! C4 a* K6 e 8 b% l4 j( z, a! Y, l9 r* t; Z
( u1 {! t$ w' C* d8 c 3 R# @. H6 P J4 f
: ~" k3 t! `; U; i1 F6 |" h4 }9 J
. O! \( o; L$ \8 Z B; q& W6 |
3 `7 h( ^0 g3 b4 v8 H2 G, a The difference A-B is defined to be the set of all elements of A which are not in B.
4 }' M/ N5 ?" x5 S8 @2 p E3 j
8 V+ L; O2 m" n0 Y, o
A real number that cannot be expressed as the ratio of two integers is said to be an irrational number. 6 z; q/ g; f6 j* u6 ?
, o$ O5 s0 D! L1 R
/ w( w" T N( ~' G2 M# M
Real numbers which are greater than zero are said to be positive. 7 `. j6 d6 A/ q6 t
$ x2 l& J8 j7 n
( }/ N8 H$ a1 B 0 o" V- L* R# `+ v3 g, `5 ?( J# ?$ R8 [
. ~7 F3 t$ \/ s/ A e! d: l: ~5 {' a, J) S* S$ P
|
+ h2 r+ k# u4 J define
' E, n) u! R2 }& v3 o; t
' e% i/ \! G6 ?" h6 Q 7 l2 d, t% [8 _2 H3 E2 f
call
6 s2 ^! N x' i3 L! T
% g7 J5 Y0 F* X7 W |
& [4 b' x E, v3. We something to be something. 8 S% c3 B: I: l. j$ I C
3 F1 C' [# X% A# [ A {
2 Y* u5 |/ N \6 Y: h" ?
! k" d3 b$ z" {9 c; c
& _9 J; w( [! ?4 T {; `/ `- v* d' t 9 D1 R2 C1 b, n$ p
& v. W" h( Y/ N! t, o
3 q4 k. o9 g% d, e! Y. K" y i$ Y) l ; T A- j- q* N! y
We define the intersection of A and B to be the set of those elements common to both A and B. 3 T* Q2 ^7 ~+ P9 F; O% k
! `: j* d8 t2 t1 ]; F& c
; ]5 v) q& x5 M We call real numbers that are less than zero (to be) negative numbers.
) h" Z( {# R. j' ?7 q
' F$ }: k" b. A. U, v7 a9 W
3 H( e/ s+ H7 I/ t0 S- E" L 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: 3 {. t" ]& v" d! L% S
$ m" w) o T: S! E
) g' g, q* R% R) o# j- C ( z8 J5 k2 |: ~
' D$ d8 Y9 u9 a, V |% O! A
- f! v! ~7 @# m9 ^ " X# L( |" c6 g& ^! m3 h' c
0 W/ A+ K. O ^ E1 \0 s
$ F" F- j/ X* ]- F9 u+ r/ e
/ E: K4 @3 D" R+ z# F5 P
N: |" B% M7 J; b" T4 `+ v& `0 K3 B7 k: P# x2 `
|
" X! ~. L. K2 ~8 R1 _5 | is called
8 _- I$ K! Q3 {, |) C! z A+ E
9 [9 ]4 {' n+ p6 H/ g/ ^/ R0 b 7 L; ?$ ~: X5 L2 N
is said to be $ W( R$ m0 h& } Q) V
5 H* V- I6 z: L4 B( Q; g3 w% M
9 g0 z( n' r9 N6 t. ] is defined as
( N: N+ W: u; p- g! U3 b! W! k% Z! B. @; r5 d
+ r9 Z: H; t" l/ b* x2 D
is defined to be
" [8 |+ S6 W9 r9 D6 ~8 K+ m( m* J9 K) R9 n& f8 x3 {' M
| ; d2 z X* d+ ] |) E
Let…, then…
& \4 `0 S. z# o& h* Y4 W
: r! W7 F/ F# u ( } [9 w" H: ~! J4 N
t" v& Y8 B7 y, L8 h( o, W
2 v. q6 R( ~* R8 z+ r6 K% B + @* Q) Y3 r6 K. W6 T# A, X
( ~% y; f6 M9 }
* n" D2 ~% d# X$ j, P. l( y ! P( k! e7 o3 {, B6 g' [+ X; M
2 n4 w& h) _# {* l
) i# w4 S# W& o) l2 z
, {1 d9 P& W. L9 q- P 7 D7 o4 M1 ? V- W
b l( V( \. @* l( A4 W+ \
# J! J; u: f7 i, }! u T9 D
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.
7 k6 p" `0 h0 P- H5 h& q1 r2 h7 L
3 F5 z$ a$ S" w 8 V$ V: i+ I; s4 n. ]
Let d(x,y) denote the distance between two points x and y of a set A. Then the number 2 K1 `2 f) {' V- J
- j6 z# o* n" _* G
+ Z2 A9 V }! J& w4 Q) ` D= 7 a# o/ Y7 I. n! x, g2 m) d8 y
' H+ G; F8 Q+ Q; z9 m: B , ?& M! ?: C. y4 x" b
is called the diameter of A.
7 d% t, D" u- F' @, `* @/ a+ y' m* l& c7 u8 \) E: j
8 X, V+ g" }4 ^: u' l' P 5.如果被定义术语,需要满足某些条件,则可用如下形式: $ Y( J, ` }# `7 |# H$ v
0 ~# Z8 V5 t ]6 p
# Q7 h8 h) o# C8 a% \8 }
% C' U; k/ c: b9 Z) p6 L% f- X {8 M
# H! N- P* v# |) u+ r; M& s3 ]1 V4 S+ ]
|
* }" G2 K; ]- {, s5 r v) d* K3 w! j is called : `, z' [: `6 d" l) z
+ p7 @+ I5 ~) N' l2 Y % p1 Z% q5 f b
is said to be 2 ~; C7 ~+ Q Z
5 i! M! _: E9 u6 C8 j: B8 E
6 ]+ d# P |9 y is defined as
5 T) Z) x# e: ]2 V" I/ }) f1 k+ E5 _$ b }, F
& o6 G* o+ s7 C, m$ R6 {
is defined to be
& N, q/ }% F4 v6 H3 e% ^: [& |
| ! c7 ]4 c4 y' C& P
If…, then… $ E0 e2 B- {7 G @, d
0 R" [6 e) n. j( y0 U* X8 M2 `
( [# ~1 ?, @" C9 |* {# G
7 B- l. y, W7 Q/ m# O2 ]4 D! _; a# g W. `0 y/ x/ E
* @$ e: }5 d" {/ g3 x
6 ?( s. I+ e j/ c+ C) w- V& o1 g! m+ @* X6 j+ W2 c$ [7 ^
' |+ L0 F8 M) }5 q8 e 1 s' k! }# t& a5 M$ p- x+ r
+ U( f8 D! f$ a! G7 h
! l5 ?( D M0 `8 U" I0 q
1 a ~+ Y0 n! x# E7 _- n
- | a+ H, k8 q $ |. {1 G% Q4 x
If the number of rows of a matrix A equals the number of its columns, then A is called a square matrix.
) a( i, T3 n5 ]( _8 J' a" X
3 g6 T4 ^6 f: D0 I
; \9 _ N! C8 f5 O: T If a function f is differentiable at every point of a domain D, then it is said to be analytic in D. ! F$ A; s$ ^/ i, S1 r# x
( {) K8 v9 B; x* J2 @
; U3 }, }! h4 h: e% e 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: 0 e+ E& ]$ I; E
2 x+ x% |0 I3 r( }
% _# d9 z) j9 \8 U ) q5 ]) @* H) w* {2 z5 G' R4 L) F7 w" ?
) [5 ]. W! {: c6 S4 b
3 _$ o. g- z% Q3 z! X! `' L1 u) Q; F
* E4 E$ a$ z0 C; ^. d0 r7 r, V# U, v8 g! C9 |0 S" e
is called
, {$ p6 _4 _2 ?& w) |4 }- Iis said to be |
$ d3 o8 u0 ]& B- l$ ]0 Z# `' l. B" w' T" q6 p s. Y& e
' B3 H& o( Z, {9 H3 \+ |
* N7 e$ i. X" n. D# m" G ~
1 j6 ?) ^7 h; y/ b# Y' @/ `, b, P9 V; B) V2 {
Let B8 s5 U3 y5 N4 ?1 d. T
Suppose | …. If…then… …
2 S2 s {" _/ i# s( n3 d9 g, M0 u- {7 }
' S" m$ O1 b$ i7 c9 r. D4 d6 @4 i
; m* U# Y4 ?' Z3 F# k K& [4 |
& `: `2 h7 a, j! |6 E) L
0 o1 d2 R% Q" k$ x' p W 4 N, I) W8 b- I: k1 z5 N
5 b. C I5 q9 H/ k" I1 H. V) C
! V! I& t* J$ w8 n$ ?9 s0 K 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. 3 J5 ^- D0 g, S9 C6 s
# _3 E3 J1 `+ a1 {# Z& n
5 C+ l& ] L' o @ 7 g$ {& ~4 k, C0 J2 c0 W
( Y% @# r0 [+ K! ~' u+ @! T
|