According to my chemistry textbook, 2-hydroxy-1,2,3-propanetricarboxylic acid is represented as:
But 5-bromoheptanoic acid is given as:
In the former nomenclature, propane is taken as the base chain while the COOH carbons are not. In the latter one, the COOH carbons are taken in the base carbon chain in the nomenclature. On checking NCBI Pubchem, I found the following:
Why are the carbons of carboxylic acids excluded in the former nomenclature but included in the latter?