Add the following as a sub-rule to the rule called Bricks, entitled Sloping Bricks:

A sloping brick is a non-standard brick. Sloping bricks are assorted.

A sloping brick must have the following qualities:

* A colour, which must be one of Black, Blue, Green, Grey, Orange, Purple, Red, White or Yellow
* Dimensions, which are recorded in the form [z]x[y], where [z] and [y] are the brick’s dimensions along its length and width. The dimensions of a sloping brick incorporate the slope, as described below.
* A slope. A sloping brick may be sloping on one or two of its sides, and is referred to respectively as a 1-slope or a 2-slope brick. This is notated as “S[z]” and/or “S[y]”, where [z] or [y] are replaced by the respective dimension as per the bullet point above.

The Value of a 1-slope brick is the product of its dimensions plus the size of its slope, i.e. either S[z] or S[y], as appropriate. The Value of a 2-slope is its the product of its dimensions plus twice the size of its slopes, or ((S[z]+S[y])*2). All sloping bricks have a height of 1.

Add the following as a sub-rule to the rule called Bricks, entitled Base Bricks:

A base brick is a non-standard brick. A base brick is one-fifth of the heigh of a standard brick (i.e. it has a height of 1/5).

A base brick must have the following qualities:

* A colour, which must be one of Green, Grey, or White
* Dimensions, which are recorded in the form [z]x[y], where [z] and [y] are the brick’s dimensions along its length and width. The [z] and [y] dimensions of a base brick must always be even and must always be at least 10.

The Value of a base brick is the product of its dimensions divided by the sum of its dimensions, or ([z]x[y])/([z]+[y]).