** Multiplication of units
(Clothes made of priced fabrics; Fabrication)
A system of assembling clothing from a pattern and materials; both the pattern and the different fabrics have associated prices.

When we make a new kind of value, the new named values can themselves have properties. That is convenient because, for instance, we might want to associate a material (itself the property of an object) with certain features, such as price.

	{*}"Fabrication"

	Section 1 - Procedure

	A material is a kind of value. The materials are silk, velvet, cotton, and wool.

	Price is a kind of value. $1.99 specifies a price.

	Area is a kind of value. 5 sq yards specifies an area.

	Cost is a kind of value.. $1.99 per sq yard specifies a cost.  A cost times an area specifies a price.

	A material has a cost.

	The cost of silk is usually $5.75 per sq yard. The cost of velvet is usually $9.50 per sq yard. The cost of cotton is usually $2.29 per sq yard. The cost of wool is usually $4.75 per sq yard.

	A pattern is a kind of thing. A pattern has a material. A pattern has an area. A pattern has a price. The price of a pattern is usually $9.99. Understand "pattern" as a pattern. Understand "patterns" as the plural of a pattern.

	After printing the name of a pattern:
		if planning:
			do nothing;
		otherwise:
			say " pattern".

	To decide what price is the material price of (chosen item - pattern):
		let C be the cost of the material of the chosen item;
		let A be the area of the chosen item;
		decide on C * A.
	
	To decide what price is the overall price of (chosen item - pattern):
		let P be the price of the chosen item;
		let M be the material price of the chosen item;
		decide on P + M.

	Understand "plan [material] [pattern]" as planning it for.

	Planning it for is an action applying to one material and one thing.

	Carry out planning it for:
		now the material of the second noun is the material understood.
	
	Report planning it for:
		say "You lay plans for a [material understood] [second noun], running [material price of the second noun] for materials and [price of the second noun] for the pattern itself, for a total of [overall price of the second noun]."
	
	Section 2 - Scenario
	
	Joanne's Fabrics is a room. Joanne's Fabrics contains a pattern bin. 

	The cape is a pattern. The material of the cape is velvet. The area of the cape is 9 sq yards.

	The bodice is a pattern. The material of the bodice is silk. The area of the bodice is 2 sq yards. The price of the bodice is $11.99.

	The cape and the bodice are in the pattern bin.

	Test me with "plan silk bodice / plan velvet bodice / plan velvet cape / plan wool cape".