<prompt> Kujenga mara kwa mara kujieleza kuthibitisha namba halali ya simu.  <response>: Mfano wa kawaida ambayo inaweza kutumika kuthibitisha nambari ya simu ya kawaida ya Marekani katika muundo 123 456-7890: d3 d3-d4 Mfano huu wa kawaida unavunjika kama ifuatavyo: - inathibitisha nafasi mwanzoni mwa kamba. - inakidhi kizingiti cha kufungua. - d3 inalingana na tarakimu sawa na 0-9 mara 3. - inalingana na kizingiti cha kufunga. - Alama ya nafasi inalingana na nafasi moja. - d3 inalingana na tarakimu sawa na 0-9 mara 3 hasa. - -d99999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999 