And¶

The associations below it are all needed at once.

An and is a complex: every gene below it has to be expressed for the reaction to run, and the loss of one of them stops the reaction. It holds two or more nodes, each of which is an and, an or or a gene product reference, so the operators nest to any depth.

The report shows it as the branches of the tree in the inspector of a reaction and links the nodes below it.

Attributes¶

Every element of a model also carries the common attributes of SBase.

associations

The order of the nodes carries no meaning: an and is a set of conditions which hold at the same time. The report keeps them in the order of the file.

• 2021003 (error): An <And> object must have two or more concrete <Association> objects: <GeneProductRef>, <And>, or <Or>. No other elements from the SBML Level 3 Flux Balance Constraints namespace are permitted on an <And> object.

Validation rules¶

• 2021001 (error): An <And> object may have the optional SBML Level 3 Core attributes 'metaid' and 'sboTerm'. No other attributes from the SBML Level 3 Core namespace are permitted on an <GeneAnd.
• 2021002 (error): An <And> object may have the optional SBML Level 3 Core subobjects for notes and annotations. No other elements from the SBML Level 3 Core namespace are permitted on an <And>.
• 2021003 (error): An <And> object must have two or more concrete <Association> objects: <GeneProductRef>, <And>, or <Or>. No other elements from the SBML Level 3 Flux Balance Constraints namespace are permitted on an <And> object.

Related elements¶

• GeneProductAssociation: the genes a reaction needs, as the tree of operators over them
• Or: one of the associations below it suffices
• GeneProductRef: the leaf of an association: one gene product the reaction depends on

Specification¶

SBML Level 3 Package: Flux Balance Constraints, Version 3 Release 1, Section 3.12 (Olivier and Bergmann, COMBINE specification).