E
|
=
|
mc2
|
Token/Identified
|
Process: intensive
|
Value/Identifier
|
Energy
|
equals
|
mass multiplied by the speed of light squared
|
Token/Identified
|
Process: intensive
|
Value/Identifier
|
mass
|
multiplied by the speed of light squared
|
Thing
|
Qualifier
|
multiplied
|
by the speed of light squared
|
Process: material: abstract
|
Extent: frequency
|
by
|
the speed of light squared
|
minor Process
|
Range
|
the speed of light
|
squared
|
Thing
|
Qualifier
|
the
|
speed
|
of light
|
Deictic
|
Thing
|
Qualifier
|
squared
|
|
multiplied
|
by itself
|
Process: material: abstract
|
Extent: frequency
|
by
|
itself
|
minor Process
|
Range
|
In spoken mode, the content of mathematics is realised by the phonological system of language. It is only in written mode that the experiential content is realised by a field-specific graphological system.
By the same token, unlike non-linguistic semiotic systems, mathematical equations can be read aloud (e.g. in English, Arabic, Hindi, Mandarin etc.).
It is not the expression plane that determines whether a semiotic system is linguistic or not, but whether or not its content plane is stratified into meaning (semantics) and wording (lexicogrammar). That is, whereas linguistic systems are tri-stratal, non-linguistic semiotic systems are bi-stratal — just content and expression. Non-linguistic systems therefore do not afford grammatical metaphor. Mathematical equations, on the other hand, make extensive use of ideational metaphor, with sequences of figures being realised as a single participant in an identifying clause, as shown above.