課程網頁中 基本spec中提及
1.6 <statements>
a. assignment of expressions, where expressions
can have variables, real-constant,
integer-constant, (, ), +, -, *, / and "uminus".
assignment is ":=",
b. input statement %% it's legal when sysio.h is included
READ(single variable)
c. output statements %% it's legal when sysio.h is included
WRITE(single variable)