# Semantics of Ampersand

## (under construction)

Given:

- a set of concepts
`C`

- a set of relations
`R`

. Every element of`R`

has shape`r[P*Q]`

, in which`r`

is called the*name*,`P`

is called the*source*, and`Q`

is called the*target*. `r[P*Q]`

in`R`

implies that`P`

in`C`

and`Q`

in`C`

.- four predicates on relations,
`uni`

,`inj`

,`tot`

,`sur`

. - a set of tables
`T`

- a set of attributes
`A`

. Every element of`A`

has shape`a<t,c>`

, in which`a`

is called the*name*,`t`

is called the*table*, and`c`

is called the*type*. `a<t,c>`

in`A`

implies that`t`

in`T`

and`c`

in`C`

.