Attributes. Our Ultra-Structure system represents the various attributes of entities using ruleforms (tables) similar to these. Panel A: Simplified BioEntity Attribute ruleform. The factors include a BioEntity and an Attribute, while the considerations include columns in which typed values are stored. These rules can be read in plain English: "the average mass of carbon is 12.0107 daltons", and so on. Panel B: Attribute ruleform. This existential ruleform is used to define various Attributes, similar to how the BioEntity ruleform defines BioEntities. The "Value Type" consideration is used to allow software procedures to find the appropriate value column for a particular Attribute. For instance, the fact that the "Average Mass" Attribute has a value type of "numeric" indicates that an animation procedure would look in the "Numeric Value" column of the BioEntity Attribute ruleform to find the average mass of Carbon.