“…But this is not the only duality for symbols. When we perceive the symbolisation of an object we may simply have a surface or observational view (Thomas, 2001), but in order to get a mathematical perspective of what it represents we have to interpret what we see using our mathematical schemas (c.f., Booth & Thomas, 2000;Thomas, 2006). This process of interpretation of the symbolisation, or representation, may require us to interact with the figural-concept object (Thomas & Hong, 2001), giving rise to identification of the object's properties, often underlying operational invariants (c.f.…”