appendix sectionnotation

Corrected simple-object inference

symbol	meaning	first
symbol	meaning	first
$\emptyset_{r}$	empty finite row	definition 26.1
$r [a \leftarrow τ]$	right-biased row update	definition 26.1
$Π (r)$	record type described by row $r$	definition 26.1
$has (ρ, a, τ)$	atomic shared-row presence obligation	definition 26.4
$σ_{0}, σ_{1}$	incomparable absent/present schemes for $W$	equation 26.5, equation 26.6
$r ‖ ‖ r^{'}$	right-biased record concatenation in Wand’s 1991 calculus	section 26.5
$Π_{L} (d_{1}, \dots, d_{n})$	finite-label descriptor record in Wand’s 1991 calculus	section 26.5