This is a followup to my earlier question about the tones in the word "豆腐":
On their own "豆" and "腐" have the tones 4 and 3:
As a two-syllable / two-character word, "豆腐" has tone 4 but "fu" has tone 0 / tone 5 / neutral tone:
dòufu. At least according to the English Wiktionary and Google Translate.
Is this a normal tone sandhi rule that fourth tone followed by third tone becomes fourth tone followed by neutral tone?