Which statement is an explicit Al-Quduri rule rather than merely a classroom assumption?

Kitab al-Iqrar: Connected Exceptions, Quantities, and Cross-Category Exceptions

• The dinar or qafiz exception deducts its value
• A dinar is always worth 12 dirhams
• A qafiz is always worth 18 dirhams
• Every garment can be deducted from a monetary admission