|
数学专业英语-(a) How to define a mathematical term?
' L6 X7 d! s. g% Y- `: y. T
7 Z! @9 `+ ]( V4 e( ? + P( b$ x: _' S J7 O! E _
9 Z% h M, M1 R \
1 `* i" r3 k% ^) ]" k& b6 w& n( ?
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。
: z5 B% ~+ P( E) g! P$ T6 }8 X! s% i5 _
+ z& @/ n) ], _& |% e
) q2 @: Q% j2 z2 m) c
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。
% X5 x8 G Z/ V+ Z& }. D 5 i9 n) E; ~) N$ T2 Z# c
/ s9 R0 X. |/ d3 {# l1 R9 ?; ~; Z 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。 + t0 x9 W5 L( t0 }# p
& g2 I5 r9 J" ]2 U' e
* e0 Q" j! R7 R
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)。
/ b# G) R" D, P# i4 u
; a& F1 K/ ~8 f+ t% L; P. x4 {
3 w6 [$ u9 W, ]3 s9 ]* L 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。
1 \# Z+ Z# t, K 2 z% V6 B1 K9 z2 k2 ~; w2 D' J
% ^1 L# P0 }- j `, v( I
1 U" ]* Q5 k* V# G$ V; {2 ~ T- O5 X* \
) w G3 z+ \. O$ t + J3 ~9 S' O/ ?: k4 b
0 Q& v3 Q2 P. b: b. u' Y
2 e; ]4 _+ Y7 { p (a)How to define a mathematical term?
x. [8 j& n6 H+ i, {; n5 `' d* @, d
! {$ e' m5 |: Y8 q$ N' r( c1 T( @8 ]2 ^( q$ Z4 p' ~# h. N3 x: h6 P0 F2 b
6 B( V+ d$ p }' s
: \* |8 K) T- O6 s1 M
. W+ T% c9 q6 ]5 y5 Z3 u. a
& C8 c1 u1 r7 y) f
|
9 c* S+ I/ ~9 [( Q4 Q2 ^ is defined as : e: y0 d! ]+ u9 I- p7 ]/ X7 O
- x: Y; A2 o; d N3 J" b0 {, f
n* W( L% C$ h% P& @. n% m$ [" F& J) } is called % [9 X5 N! A0 |, [. r! R8 i
3 T1 X( L' e) P6 Y( i" g8 | | ; v7 l m) a+ l; K, g) v: D( c( ^
1. Something something
8 t) |5 g6 ^9 L3 `
8 ?5 w% B7 ]5 y8 v
6 f' {/ M4 Z: {2 ], Y
. o! S) L2 y. r: E
! x I1 m) u a8 y% ~
" D Q e* ^3 x; w2 ~
0 r! t3 U# A: G1 l ~! g0 P. T' V
: [* @* V& Y X; f
- E0 k1 p$ @# I The union of A and B is defined as the set of those elements which are in A, in B or in both. 7 R6 W1 A, J5 D. I4 C% P3 Q
3 w( z- d6 }( x2 v( ]1 k2 A; U8 h
; V& X; f9 K! |' ]( w2 }
The mapping , ad-bc 0, is called a Mobius transformation. ; _9 W) t/ t7 F2 P
7 \; f8 s7 `' v! F 5 k$ R, |! ^. W
2 }% t& s" l! _2 M1 [* ]) z
- w* p7 f M% `) t8 J& g* s1 H
2 ]$ Q) Y& O1 R# R: n|
: n* I- L% q8 H% u is defined to be
# z5 O& m. P: ]: X! ~% u
9 w! b! K5 B4 f8 T
* a; u! w+ E! I1 J0 H8 |: K- E6 v is said to be
/ Y4 [4 Y! x c, @. n( W% b7 j
4 s! w9 N: E) F5 g2 Z: a2 ?4 b; H |
0 J& ~# U" J, h$ g* n' ~$ e7 g2. Something something(or adjective)
$ V- y# p! N6 ], U [+ @( @' Q- i! ?; Y S% ]0 T( { i/ b/ y- a
5 E$ }+ k7 ^) D4 d1 I H7 O 0 O* u) \ r, O; C2 B: ]. f
+ N- Q1 F: M$ ~% i- |7 q' i
1 W3 j" s4 Y4 p9 [
, {# R! A7 W$ e7 z
+ i! b$ s' K9 U) |2 Z0 L/ S' Q # }; h" x: p9 `! O- P
The difference A-B is defined to be the set of all elements of A which are not in B. . s. _) v6 X% w7 z
3 T& Y0 r5 L- X; A$ _9 ^
2 A% C5 M. }: G, ?, A' a! G& G A real number that cannot be expressed as the ratio of two integers is said to be an irrational number. / d+ v* d v2 T$ ~5 Q: }
+ i" B9 p. i- T% e0 x- t4 {8 ]
* R% \: }+ ~: r% W$ d, H* H Real numbers which are greater than zero are said to be positive.
" p" Z, V: a8 s( h- _* ]6 S6 U: ^* g/ o
# a* d% K6 Y* `
0 Y# H) r7 z H1 Q1 S4 b2 N1 G c( ~) n; j; S+ H
1 `% ^4 q: b4 Z|
# g2 X: E2 \- q! _ define $ m8 o/ ?6 V$ z# r, z9 b: @
* g9 g0 N/ a3 {$ e7 b+ o
. V( w' N' d, n9 z- ]3 V/ ? call
& B2 a* D1 Z1 a3 `" _5 L8 h
/ L* f+ J1 l+ ?2 m |
" y3 i2 n/ I5 f* l: F3. We something to be something. % B/ Q* y" ~2 @; q
9 _9 ?4 z5 J7 y! Q* e
/ m0 c8 a" `' c
$ e' u9 Z$ y/ v; m! J6 Z$ x: X$ ?
+ M, ?& Q; w' b9 e0 [
1 E# o B; }) `
/ v' w/ C% B! x0 I# A! w6 B/ W 1 ]8 ^" K- `3 `
We define the intersection of A and B to be the set of those elements common to both A and B.
5 }3 U2 {, e- I a! `0 {2 ~
2 k1 F1 w$ ?% ], D4 U( Q ! E3 ]4 S2 F5 b! K: |2 P
We call real numbers that are less than zero (to be) negative numbers. 6 N) R e5 ]" E% u9 y
8 p6 G9 A; }" p! |9 Q
, u0 G$ R9 J2 g7 I, U f 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: e, z6 c" K+ M3 R6 i2 r H9 y
, R Y2 L0 U3 x/ [
$ D$ ?) y) X6 U( e# J , _: _7 V) Y. k9 p/ L0 B1 P2 U; B
( K0 Q! F% z+ o( @$ ?- b6 A7 X, ^
9 ^' v3 w7 N1 W# H' N( z# J
' E* H. l A! W$ ]4 O4 \5 m7 |. O7 Z6 h: ?
$ b/ z) g3 y8 F/ z! A 4 }8 h% {" M# X
" G7 E* N! H9 d9 |7 \) T& j9 e7 L" d, i
|
% S. A- u5 Y: F! X: |* `- v/ ? s, L* c is called * D4 [5 A4 D, o
( C* a& X% ?9 P& B+ o- K+ v% h
7 Z* n8 {0 [' h& T8 v is said to be
# Q8 y/ d, q( |% s9 B3 |# F
) w) m( a) [5 A: ^ 7 O/ @- Y6 m) l
is defined as 8 N" q1 H4 F) F' A$ r
* c! ~$ }: t3 @! A) H
6 R# L$ Y3 E% Q: s; I
is defined to be ) d: R# f3 o, z/ B3 J& V
$ x( j' P: i/ G5 k4 a
|
% t4 l9 ^$ b- ^: i: \6 Q Let…, then… D j& ^ f7 q( k6 [8 m* `8 N3 G8 J p* M
7 p6 W& X5 \4 t# w7 M* x) f 5 [+ d9 `4 U( ?/ z, p* _) A
! H2 _1 d# f* a, t& }
! B# l3 D* _9 q3 @' l
8 ~4 X' o: e9 j3 H1 y( v! f. v
3 P4 ^" C( [- L$ F" }
1 u9 x# H6 J0 Y/ a5 Z
; I7 G: l4 u# Y7 E* _' p
# Q( c7 H3 c! D5 R- V& F
' ~9 e) e* N/ Q! L3 O
$ u! M3 y1 {7 v( A
0 K7 u1 h0 Q& c, }2 ^
. }2 c) S- h) e- ^ 1 \7 R2 h2 U* R, I
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.
" p6 S9 j) p; d: J: f0 v( [- K8 z
% v8 c1 t: H2 k! c5 A
, e1 ~! {3 S! _( U2 V3 L Let d(x,y) denote the distance between two points x and y of a set A. Then the number
% F% K2 X0 L' S) j6 e
: z7 H+ P% [' K) ?; v5 o ' E( \/ n+ i/ y$ }5 l# w4 F
D= 3 q$ e3 q3 H$ C2 m# y
6 w: ]/ U3 {( ]" c, E
, z3 [9 x; }4 A is called the diameter of A.
8 O' {5 Y5 ~4 J# {1 ]' O6 u3 s5 y6 e, ~% W! P# ^# q1 r6 M3 I
4 Z3 a+ m- x/ O* n
5.如果被定义术语,需要满足某些条件,则可用如下形式: - e, k+ @! W- ^! N( ^6 Z
2 p7 z" {( m2 W * g& @) P- W( C- z% C$ z
) ?! T7 g3 \ w, T/ T; D
- L+ Z0 F$ O6 m4 F; B* f2 m; z/ P5 o8 g U* F) Y+ h* t6 y; U
| 4 \1 R4 e/ z8 ~& D
is called
; y: G( W0 C5 u0 F' O
$ @9 K; I+ p4 Y6 K% _% w! `0 g
5 A! M7 V" b% ~! @ is said to be ; g! x$ \, P4 \: K, ?9 R/ p% ]' E6 Y
$ o" j- u* l% _, P
3 Y* U& w a) X; z
is defined as * N) ?: z. S3 v9 H+ [+ A: @$ H
9 M5 e( a K, F
3 [; l! D e9 A" t2 | is defined to be 1 j2 ?: f# U+ `
5 x, b0 X U1 T" \9 t. L | ! \/ Z$ {9 H; I3 l* l) Y
If…, then…
2 U. B H5 T7 \7 i8 C" |' J$ d) u
% ?* R3 f: R( {. z9 M0 `: H! r' [. i / T, F4 i3 n# L7 [: ?: d
3 J$ X; ^. s' P! J7 y8 G8 Z4 P
( H6 T; n; j1 _. }' ]3 M$ g
1 |" ^8 Z$ q" b8 L- |5 m
% W" B, B9 }# p! O: q
1 [4 N' U. t; N3 F' [ & O- D3 p! v% {2 g
' L I& z1 @3 `2 R
' l: Q: R. f' a
1 O: I' v& l" {9 ` 1 x8 b2 l" G4 m7 _" ?( ~
( [4 S$ q0 x& i: r% q2 H
. a" H7 e& s" B
If the number of rows of a matrix A equals the number of its columns, then A is called a square matrix.
) u8 z) B6 h* b# } W
% u% T7 j. z y$ y" z% g( m : m8 }7 ^8 J3 x3 g" r' T; M; C
If a function f is differentiable at every point of a domain D, then it is said to be analytic in D.
! p/ E4 b, i; a* b2 O, z1 k4 w0 T# P" ~( q" o+ \
/ H: H! r1 i2 T- r/ ~0 K7 t: Y! t7 K
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: ) O) ~* X0 `, O# g. {. a7 i
' I% h# ^; ~4 D' d4 Z
: N2 U' M" G, [4 ]
' M6 c2 | W% X# p, X! S0 f
5 O9 N6 T4 M3 w2 l7 y/ m* P8 ^& G2 | o; t4 Y) p
3 R6 c4 W+ `+ z+ I% o; ^$ F/ u
! y( _% S X' H
4 t6 ?! s" Y9 z) s( vis called
$ @: s1 A* g" f: T5 X! Z e Sis said to be |
; f4 [8 ^% n6 [8 E* F: _: j
1 b- l5 w% \, y( [/ a, `
( p% Q) v. v$ a4 ]- t5 B7 r# b0 h5 h4 I& k$ M/ ~; _, w
3 h0 Q6 X( E$ u0 Q: ]! A5 k. U0 p9 W* ?5 s! ~1 {
Let 6 Y. d1 o3 f! C* X1 d' Y
Suppose | …. If…then… …
# Z. x/ Q1 n2 S) p" D( M' p$ k U- S$ o* V1 S
5 z, k f2 T6 k
' E% F. ^! y3 w; q- A! G( [* }$ a; G: z% n8 Z; d/ o
8 x' b( @4 [# X, n$ m# j3 k6 Y
6 a, ^0 z6 t( C3 U. G6 D
$ Y; a$ d! [6 Z/ T
7 A: _9 Y5 X# A- K- Q9 |3 d% ^
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.
9 o7 m+ x$ W+ [; z8 V. R
- H& O" [7 |& ^" J/ ^) c
- f$ O f; g5 L4 S# | ; {# f$ q i; i2 I3 l, h
* P; g6 D5 W# ^
|