Examples
# Set/Get/Variable Reference
# Save a widget and link a textvariable
aitcs new rec
aitcs new gui   
set fld preference
rec $fld Tcl
gui $fld [entry .e -textvariable [rec& $fld]]
[gui $fld] insert end /Tk
string length [rec preference]; # 6

# Get/Set  
aitcs new things
things a 3
things b [expr {[things a] + 2}]
things c [expr {[things b] * [things a]}]
things c; # 15

# Setto/Exists/Unset/Variable Reference
aitcs new fruits
fruits= apple orange pear apricot 0
if {![fruits? peach]} {
   fruits= peach 0
}                
array names [fruits&]; # {apple orange pear apricot peach}
fruits- p* a*
array names [fruits&]; # {orange}
              
# Lappend       
aitcs new store
store this one  
store+ this two three four five
store this; # {one two three four five}

# Incr
aitcs new counters
counters cycles 0  
counters+= cycles
counters+= cycles 2
counters+= cycles -1
counters cycles; # 2

# Make Exist/Exists
aitcs new cow   
cow!
set cow(sound) moo
if {[cow? sound] && $cow(sound) eq "moo"} {
   puts "Standard English Cow"
}

# Command Reference/Variable Reference/Incr
aitcs new callback
callback count 0
after 1000 [list [callback&&]+= count]
vwait [callback& count]
callback count; # 1

# Destroy
aitcs new tmp
tmp count 5
tmp+= count -1
tmp count; # 4
set fqarr [tmp&]
info exists $fqarr; # 1
tmp---
info exists $fqarr; # 0
tmp count; # <error>