表达式3: "k" equals left bracket, 0 , 1 , ... , 20 , right bracketk=0,1,...,20
equals=
00
11
22
33
44
55
66
77
88
99
1010
1111
1212
1313
1414
21个元素列表
3
表达式4: "P" left parenthesis, "j" , right parenthesis equals Start sum from "n" equals 0 to 10, end sum, pdf left parenthesis, "a" , "n" , right parenthesis pdf left parenthesis, "b" , "j" minus "n" , right parenthesisPj=10∑n=0pdfa,npdfb,j−n
4
表达式5: "P" left parenthesis, 6 , right parenthesisP6
