定義
Digit=0∣1∣2∣3∣4∣5∣6∣7∣8∣9Digits=DigitDigit∗ϵ=空串Signed=ϵ∣+∣−
無符號整數(UnsignedInt)
UnsignedInt→Digits→DigitDigit∗→(0∣1∣2∣3∣4∣5∣6∣7∣8∣9)(0∣1∣2∣3∣4∣5∣6∣7∣8∣9)∗
有符號整數(SignedInt)
SignedInt→SignedUnsignedInt→SignedDigits→SignedDigitDigit∗→(ϵ∣+∣−)(0∣1∣2∣3∣4∣5∣6∣7∣8∣9)(0∣1∣2∣3∣4∣5∣6∣7∣8∣9)∗
無符號浮點數(UnsignedFloat)
如:2.5e10,3.333,4.5E−7等
Fraction=.Digits∣ϵ
Exponent=ϵ∣((e∣E)SignedInt)
UnsignedFloat→DigitsFractionExponent→Digits(.Digits∣ϵ)(ϵ∣((e∣E)SignedInt))→(0∣1∣2∣3∣4∣5∣6∣7∣8∣9)(0∣1∣2∣3∣4∣5∣6∣7∣8∣9)∗(ϵ∣.(0∣1∣2∣3∣4∣5∣6∣7∣8∣9)(0∣1∣2∣3∣4∣5∣6∣7∣8∣9)∗)(ϵ∣((e∣E)(ϵ∣+∣−)(0∣1∣2∣3∣4∣5∣6∣7∣8∣9)(0∣1∣2∣3∣4∣5∣6∣7∣8∣9)∗))
有符號浮點數(SignedFloat)
SignedFloat=(Signed)(UnsignedFloat)→(ϵ∣+∣−)(0∣1∣2∣3∣4∣5∣6∣7∣8∣9)(0∣1∣2∣3∣4∣5∣6∣7∣8∣9)∗(ϵ∣.(0∣1∣2∣3∣4∣5∣6∣7∣8∣9)(0∣1∣2∣3∣4∣5∣6∣7∣8∣9)∗)(ϵ∣((e∣E)(ϵ∣+∣−)(0∣1∣2∣3∣4∣5∣6∣7∣8∣9)(0∣1∣2∣3∣4∣5∣6∣7∣8∣9)∗))