Education that consists in learning things and not the meaning of them

is feeding upon the husks and not the corn. -- Mark Twain

... the learned have the right and the duty to use an obscure language that is comprehensible only to their fellows. -- Umberto Eco, The Name of the Rose

`
v`
0, `
v`
1, ... Value for attribute

δ`
a`
, δ`
v`
1, δ`
v`
2 Change to an attribute

<`
a`
, δ`
a`
> Tuple of attribute `
a`
and change δ`
a`
to `
a`

P, Q, T, E1, E2, T1, T2, S1, S2, ... Entity

`
P`
→ `
Q`
Relationship between attribute sets `
P`
and `
Q`

`
I`
, `
J`
, `
I`
1, `
I`
2, ... Interaction

`
I.affects`
Effects determined by semantics of interaction `
I`

`
I.affects`
+ Effects of interaction `
I`
determined by dependencies

`
I.affects`
∗ Effects of interaction `
I`

`
E`
(`
I`
) Effects of interaction `
I`

`
I`
• `
J`
Concurrent occurrence of interactions `
I`
and `
J`

`
E`
(`
I`
) ⋄ `
E`
(`
J`
) Applying `
E`
(`
I`
) and `
E`
(`
J`
) in some sequential order

`
E`
(`
I`
), `
E`
(`
J`
) Applying `
E`
(`
I`
) before `
E`
(`
J`
)

`
t`
, `
t`
´, `
ti`
, `
ti`
+1, `
tj`
, `
tj`
+1, `
t`
0, `
t`
1, ... Observation time, simulation time

Δ`
P`
(`
ti`
) Changes to attribute set `
P`
during time-step [ti-1, t]

`
T`
, `
TA`
, `
TB`
, `
TM`
Sequence of observation times

`
Rep`
, `
RepA`
, `
RepB`
Set of all attributes in a model

`
Rel`
, `
RelA`
, `
RelB`
Set of all relationships in a model

`
Int`
, `
IntA`
, `
IntB`
Set of all interactions in a model

`
LevelA`
, `
LevelB`
Representation level

`
Rep`
(`
t`
) State of a representation `
Rep`
at time `
t`

`
Rel`
(`
t`
) Relationships in `
Rel`
that hold at time `
t`

`
Int`
(`
t`
) Set of interactions in `
Int`
sent or received at time `
t`

`
Int`
(`
t`
)`
k`
`
k`
th interaction in `
Int`
(`
t`
)

`
F`
(`
Rep`
(`
t`
), `
E`
(`
I`
)) Function that applies `
E`
(`
I`
) to state `
Rep`
(`
t`
)

`
RepSeq`
Sequence of representation states

`
RelSeq`
Sequence of relationships that hold

`
IntSeq`
Sequence of set of interactions sent or received

`
RepM`
Set of all attributes in a multi-model

`
RelM`
Set of all relationships in a multi-model

`
Relcross-model`
Set of cross-model relationships in a multi-model

`
IntM`
Set of all interactions in a multi-model

➛ Transition in a state diagram

```
R(
```

`
a`
```
)
```

Read operation on attribute/variable `
a`