关系式里取余的函数是什么

我不大懂如何在PROE裡編寫程序,
但希望可幫到你.
  
a = 13
b = 3
c = a / b
d = a - ( b * floor (c))
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c = 4.3333
floor (c) = 4
d = 1 (餘數)
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