最近学习SAS，看不懂SAS的语句格式，请教高人如何理解其语法格式，好像不同于一般的伪代码。SAS的帮助文档，例如：data的语句格式.
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Syntax
DATA <data-set-name-1 <(data-set-options-1)>>
<. . .data-set-name-n <(data-set-options-n)>> </ <DEBUG> <NESTING> <STACK = stack-size>> <NOLIST>;
DATA _NULL_ </ <DEBUG> <NESTING> <STACK = stack-size>> <NOLIST>;
DATA view-name <data-set-name-1 <(data-set-options-1)>>
<. . .data-set-name-n <(data-set-options-n)>> /
VIEW=view-name <(<password-option><SOURCE=source-option>)> <NESTING> <NOLIST>;
DATA data-set-name / PGM=program-name <(<password-option><SOURCE=source-option>)> <NESTING> <NOLIST>;
DATA VIEW=view-name <(password-option)> <NOLIST>; DESCRIBE;
DATA PGM=program-name <(password-option)> <NOLIST>; <DESCRIBE;>
<REDIRECT INPUT | OUTPUT old-name-1 = new-name-1<. . . old-name-n = new-name-n>;>
<EXECUTE;>
