|
数学专业英语-(a) How to define a mathematical term?
( Q: [3 P# f6 F' A! b: Y( K+ h# z
# {0 ~" x3 q5 ?1 Y, d * Q, k2 Y) ^: u% z7 g# S) @
% `- G, U' [( E- \( K! S) \5 O; P) h+ b
; w4 U0 e" u$ h+ B" 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。
/ V* F/ S. ]" h7 t9 b- j& T, t7 j* K5 X- {6 D; l) b
% s% C' y* v% ^& ]' o M- q- I; v- _# G, d- g* z
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。
& @5 r& m0 l) c! H, K) _0 Z
, ~! f% e- ]; a+ ]( |
9 ^4 }7 P- ^9 d, B 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 x z8 c8 T4 Q& ^4 ^1 U3 ]
- D9 G* i- c1 l2 f% ~, i; u2 b
; N5 o* }/ v. V! J# C8 ^ 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)。 2 d& S5 z4 W/ L1 X
9 ?% v# r/ F E# b+ T& D3 r
# Z$ Q% R$ j. l, x# j4 d1 {! }5 D
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。
% ]/ C, }, L1 ]2 m$ r: z; H' r ( l1 O2 V4 _$ e* _* l
, ]& Z1 w$ {' B" e# h/ B0 {
9 f! F7 x0 B2 B: z$ E( _! ?* }+ N
/ ~8 ?+ d- F/ T& q' C
+ N' O, N# i$ D+ p% V9 Y 9 a7 S" V6 x; c D4 k* o" y" s
& q, Q* h v- g1 L5 L
9 q5 D' r/ F: \, w
(a)How to define a mathematical term?
, T, p' e5 L1 s% M3 |- f; U3 j) P; |3 k; E
* E& o3 M3 P3 s5 @; ~# [ g' _
g) f. q' P) o2 w& t+ v4 W
; `3 D% _2 n" ?0 `% u
& T; Q9 V7 P+ |- J- g# y
+ X% V# k3 h* M% z' c$ i0 J A| N% ]1 ^1 d8 @7 m1 ^% Z! J
is defined as . e4 I! l8 {! A% a3 X' O5 S3 l
4 n& X1 y g2 _0 [. E * m3 `5 h5 w, }- E' I }
is called - B" o9 T( b$ f" A, N7 S! s/ S" e- Y5 b
: {6 O1 N$ D3 n
| E5 Q" ]- |/ l0 j' w$ f6 R
1. Something something
( l8 J0 W6 y4 a. ?1 U4 a) [
4 f0 `- ^8 k5 l) } - b. n# \8 z k. ~
V8 {9 X- P+ v' h/ ?% o
: }; i# h% m, C, H+ r1 f0 }
7 M( P$ O0 n( Z. c# _; s
. H$ Q, g( q( }6 y$ Y. M
2 `6 _$ p! d5 D4 j# S
: n8 v2 i3 h" r& o- C The union of A and B is defined as the set of those elements which are in A, in B or in both.
7 O: _& X: C) M8 n9 S% \
- H/ @) h$ ^5 n$ S
) N8 q% }3 I( s The mapping , ad-bc 0, is called a Mobius transformation. 8 ]4 Q u1 ^. f) J
) o2 ~/ S O) Z4 C( h
2 }, @5 I7 X. c
$ ?( d* K% D {4 [
& a* X, C2 t( r3 [
5 l) j$ ^" U4 s. b| ' b' S; H6 \1 B3 j8 @+ @1 [8 S% C; ]
is defined to be 0 q' y) Q9 A! }$ n" z
. E; F. r2 D2 c# a, b! l" v
) |! F/ E5 ^4 {" F) i0 N is said to be & w8 |) x: B+ D% r: L( s
# A# ]8 S6 H2 D$ ]
|
; j# W6 H0 v. q2. Something something(or adjective)
% A. ?# d& j, ^# ?( {' k+ j& Y- ]$ E4 C
/ p1 @& Q# Z7 k J3 I) L 9 @% ^: Z5 s2 A, }, N1 p
' ` n( A( n3 R# p1 Q. @* h# |2 V9 ?5 H4 I F% l# C
; M1 y* N; J) H( M* ~ 4 j# ` J3 E4 _9 F
" L4 e G" G8 ^' r
: B* E/ f, S+ t" L1 d/ r% {
The difference A-B is defined to be the set of all elements of A which are not in B. $ z# G0 \7 w1 @$ t: c6 ?4 j
. X- r& g0 O! a9 Z! `, Q: @3 w . M2 s- _5 H8 F% J2 ^0 M
A real number that cannot be expressed as the ratio of two integers is said to be an irrational number. " D! q) M! `- Q% }- B; U
# @& J. v* R- x
) |5 c4 [7 A; D- U# s Real numbers which are greater than zero are said to be positive. 6 n/ D% }& Y+ P# _
5 V' T- D \7 [8 Y
% H1 C; B' s* K% p c% h4 T
- M# O- W0 l- z- H) V- i1 w5 x& K" e
8 V! |9 i5 N5 Q: R: ~, K% o' y4 G8 o0 H
|
$ ^0 X" ~# n, a, X' Q define : i" ~$ z* U' j* l5 ?. k0 c: p; V
- f; k3 r/ E P. z/ h7 H
: X( `$ f) p( V
call
3 }5 R* _( ~5 b; i+ D
0 r. D% a( u( a, `$ S+ D% T |
9 q, a. G! } H! O3 @5 |6 S) `3. We something to be something.
. x, N( w6 V7 s1 o5 x" ?0 D
/ w6 U6 ^) `+ ]
9 \; s2 g9 Q N5 ~3 N 4 c' ?& @) s. N2 m m
5 f( u: }6 L: V4 {( s! P, h
' Y& \& I/ V( \! a
: n" a7 e8 Z. Z% U0 E6 y- T5 @5 T, P( U5 t" E2 e0 B; j2 D
- Q' a2 O2 f6 m- C We define the intersection of A and B to be the set of those elements common to both A and B. 9 w% u8 I4 O$ `4 ^# Z$ B# M# O
, P4 f. R; H' o
' R4 e0 g. X! J* ~- h0 A& G) S We call real numbers that are less than zero (to be) negative numbers. 0 i& Y# d/ |3 z/ H
! n& T$ ^5 W, D% v
. |+ t- m) U! h3 O4 Z3 ~6 k2 ?+ 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:
4 r. @( `' r- O9 h
: w1 T; d- Y3 R# ~" y
7 }; H5 F+ E l7 u' C- z& _
3 `! m" {! E& h" y- ?% J: f; j, Q+ B$ r! a! D2 g3 R5 m( [
% g: j! t! _: Z; V% G
) a S: }! \& e) V8 O5 N( B H) M. K1 J1 c: i
. L1 `+ B! X% [% l9 H5 L0 S
$ ?' |$ i6 Q, _1 @$ L& f1 @4 K! Q6 |% [7 E) S
( f# B7 o! o' K* |
| 7 {- i. F! j$ B& R' r! B+ P
is called
2 b8 M* @9 P- j7 i. W2 }8 e Z) ]7 ^; Y1 m( w
& P% H; y& g0 B9 M. l- h; @ is said to be 1 M% C! r- _. P7 i1 A
. i3 j# u" J, b2 `3 r
/ W4 _2 A' T5 a6 X; o4 G. O0 \
is defined as
' ^( Q7 T( e+ `% ^% D+ \0 ]2 ~
* I$ y: x, e) u7 f; E
9 A0 ? k5 _; x9 p+ y5 U! J is defined to be
9 P) H- j2 y# F: N
; S# X: Q& C( t" S | 5 Q6 ^. A2 G/ Z% F/ F4 G
Let…, then… 1 {% F6 ?. h& }- x1 T
8 F7 F, V* l9 `' C, G
- \2 f* |5 d, ^* s) N) E
; ^7 W6 F7 V9 B: h+ ]' n1 A' q7 I+ G2 W
: R! r p& C! W7 j" K& @
1 O$ ` C0 g5 I1 C/ h) z" u" P% Y+ {
& j+ a, U0 }3 d. f$ D
3 D: X5 f& f7 c- i* Z% h
8 t' E0 y: Q% o
5 N+ N3 g" b# `+ R& I
9 u7 ^6 G. \) e; J
4 Q% O* v3 j0 |' J% ]: y+ m5 q + w" p; N8 C# `; ~
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. 3 i8 w5 X) Z3 ]$ ~
^5 i+ L( c- E! ` i9 O
9 `6 p$ e- A- ^) m: O6 J [7 Y Let d(x,y) denote the distance between two points x and y of a set A. Then the number - c7 L/ I8 _2 n. z; R5 J6 h( n
$ s2 f! ^7 b' y
. ?/ `4 x- x$ R
D=
' ^! _/ `* U8 E* x5 C# {
* W/ E+ g, z' O/ L6 h- L
) n {7 [; v/ C is called the diameter of A.
J4 j; a/ A% [) e* N
' j) k1 a" C0 z2 g
2 n. w3 p, X7 z2 T, D% y 5.如果被定义术语,需要满足某些条件,则可用如下形式: 5 t. `! i0 Y* Q
- ]8 C; ~; @) M; z3 C: a 9 J2 n$ S( w3 e- t5 _3 |& z
/ R) I0 I* B+ J
2 V) O( j5 i9 E5 p
' d- u% q6 _: v! b2 ]5 d0 R| 2 y. L/ Z* W/ K# a
is called
% G: \0 p& r4 v: X+ w3 [& n& T4 p% ^3 H9 ^) W4 Q$ @) F4 k
# H$ {) `- H+ ]( u S! |$ F
is said to be + F1 H' w- [, {, g% \
. F& L$ P! k8 u+ y( E8 c
( W3 o! j7 K/ |, I4 V is defined as
@) i. D$ d @0 i: v8 J- E4 \$ R
, r. r. ]7 \3 W( d: ~: ^ g
. `; h9 T% d; f is defined to be
/ Z, B2 I) B3 Y# ~( a6 |" X. j" D2 f5 y3 [# j: A
| / B8 |! X- t1 c( Q: L ~; f
If…, then…
5 r8 h5 o( ]/ i5 l7 f2 x3 k2 b- [. w
% y, t1 m$ @! U' {, G7 O: g- D. q t4 }
; G8 i7 t, `$ `: F# s5 u' H4 T, l" z$ z# B
& C! x; B" \8 e ' ~5 [8 k5 F, ?9 Y) k2 l
. u! m7 H* U# d8 A! |
3 C0 p* n# E* U G
! c8 d$ \5 V$ g: ?
9 ]/ ^' I7 E0 q5 j4 [ # Y- ?, I9 r6 u
* G- E. b& p0 a; I
2 P5 s: k4 D& W
0 V, L" r6 o F# |* x If the number of rows of a matrix A equals the number of its columns, then A is called a square matrix.
! ?. c/ F+ w2 z$ A
3 U, Y0 z8 H- A
4 W2 O5 X& I% P- M7 b+ \* Q If a function f is differentiable at every point of a domain D, then it is said to be analytic in D. ! f; g# h1 j1 K1 d
+ q" f5 z+ j* t6 q# Z * z. C& E8 V B/ o
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:
. g2 {- ?# H4 U1 b$ E
" T- K, O) X8 `: u # H& H4 i7 b+ ^9 {0 I
2 L9 f. [% S7 W7 Q; \
2 w6 R0 b8 [( w" l4 w3 p' p6 I5 a* b+ L; \( H, _
) a2 P" ^; j) ^' t( Y; c* [, ~& L# p6 X0 l( m# H" R
* H/ r4 q- ?# t, _7 m4 k
is called 0 @1 K6 ]' e/ ?" E
is said to be |
# ?$ I3 w2 M- u! U8 [' h1 Q& Q
2 k1 R$ p% l, q. ?6 c& T
9 y- c% P' k! D: {# @' C1 [; K n" H v) P/ B! o% D
4 e4 G1 h8 e# M' x. v
" S! z1 h9 y! j# M/ D+ yLet
; I& T: r2 ~! s% e. } g+ z0 E6 tSuppose | …. If…then… … : g9 v* e) _/ e) P
. g8 X d; R! f& p. U; M! s% y# p N/ z% N# O# c
1 T" X6 o& R, w3 I: a* G* D3 H3 P9 ?) q
' j4 ]2 z7 S1 K5 F + g( H0 ^6 i2 \
( ^8 i7 \0 i: ^8 t- h9 `
3 r0 d( Z( N9 {+ Z
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. ) _/ m% i' `; f" e: h% U1 h
0 M6 s i0 I1 B7 z2 h: ?5 K ' N0 E: S4 I2 W* m5 c% ~
, L( x2 q- |7 u& O2 @) ^/ w
1 }! r8 r1 [. x( M7 o0 E, X" n |