/***************************************************************************************************
|
|
Each level on a SMTInsert has a state.
|
|
|
|
The state of the level depends on the state of te botom level and on `xor` and
|
|
`is0` signals.
|
|
|
|
`isOldLev` 1 when is the level where oldLeaf is.
|
|
|
|
`xor` signal is 0 if the index bit at the current level is the same in the old
|
|
and the new index, and 1 if it is different.
|
|
|
|
`is0` signal, is 1 if we are inserting in an empty leaf and 0 if we are inserting
|
|
in a leaf that contains an element.
|
|
|
|
The states are:
|
|
|
|
top: While the index bits of the old and new insex in the top level is the same, whe are in the top state.
|
|
old0 and old1: When the we reach insert level, we go to old0 and old1 states
|
|
according to `is0` signal.
|
|
btn: Once in old1 we go to btn until xor=1
|
|
new1: This level is reached when xor=1. Here is where we insert the hash of the
|
|
old and the new trees with just one element.
|
|
na: Not appliable. After inserting it, we go to the na level.
|
|
|
|
|
|
Fnction
|
|
fnc[0] fnc[1]
|
|
0 0 NOP
|
|
0 1 UPDATE
|
|
1 0 INSERT
|
|
1 1 DELETE
|
|
|
|
|
|
|
|
###########
|
|
# #
|
|
┌────────────────────────────▶# upd #─────────────────────┐
|
|
│ ## ## │
|
|
│ ######### │
|
|
levIns=1 │ │
|
|
fnc[0]=0 │ │ any
|
|
│ │
|
|
│ │
|
|
│ │
|
|
│ ########### │
|
|
│ levIns=1 # # │
|
|
levIns=0 │ is0=1 ┌────────────▶# old0 #────────┐ │ any
|
|
┌─────┐ │ fnc[0]=1│ ## ## │ │ ┌──────┐
|
|
│ │ │ │ ######### │ any │ │ │
|
|
│ ▼ │ │ │ ▼ ▼ │
|
|
│ ########### │ │ ########### │
|
|
│ # # ────────────┘ └────────▶# #│
|
|
└──# top # # na #
|
|
## ## ────┐ ┌──▶## ##
|
|
######### │ │ #########
|
|
│ │
|
|
│ ########### ########### │ any
|
|
levIns=1 │ # # xor=1 # # │
|
|
is0=0 └───▶# old1 #─────────────▶# new1 #──┘
|
|
fnc[0]=1 ## ## ## ##
|
|
#########│ #########
|
|
│ ▲
|
|
└───┐ ┌─────┘
|
|
xor=0 │ ###########│ xor=1
|
|
│ # #
|
|
▼# btn #
|
|
## ##
|
|
#########◀───────┐
|
|
│ │
|
|
│ │
|
|
└────────────┘
|
|
xor=0
|
|
|
|
***************************************************************************************************/
|
|
|
|
template SMTInsertSM() {
|
|
signal input xor;
|
|
signal input is0;
|
|
signal input levIns;
|
|
signal input fnc[2];
|
|
|
|
signal input prev_top;
|
|
signal input prev_old0;
|
|
signal input prev_old1;
|
|
signal input prev_bot;
|
|
signal input prev_new1;
|
|
signal input prev_na;
|
|
signal input prev_upd;
|
|
|
|
signal output st_top;
|
|
signal output st_old0;
|
|
signal output st_old1;
|
|
signal output st_bot;
|
|
signal output st_new1;
|
|
signal output st_na;
|
|
signal output st_upd;
|
|
|
|
signal aux1;
|
|
signal aux2;
|
|
|
|
aux1 <== prev_top * levIns;
|
|
aux2 <== aux1*is0;
|
|
st_top <== prev_top - aux1 // prev_top * (1-levIns) =
|
|
// = prev_top - aux1;
|
|
st_old0 <== aux2 * fnc[0]; // (prev_top * levIns * is0)*fnc[0] = aux2
|
|
st_old1 <== (aux1 - aux2)*fnc[0]; // (prev_top * levIns * (1-is0))*fnc[0] =
|
|
// = (aux1 * (1-is0))*fnc[0] =
|
|
// = (aux1 - aux2) * fnc[0]
|
|
st_new1 <== (prev_old1 + prev_bot)*xor // prev_old1*xor + prev_bot*xor =
|
|
// = (prev_old1 + prev_bot)*xor;
|
|
st_bot <== -st_new1 + prev_old1 + prev_bot // prev_old1*(1-xor) + prev_bot*(1-xor) =
|
|
// = - prev_old1*xor -prev_bot*xor + prev_old1 + prev_bot =
|
|
// = -st_new1 + prev_old1 + prev_bot
|
|
st_na <== prev_new1 + prev_old0 + prev_na + prev_upd;
|
|
st_upd <== aux1*(1-fnc[0]); // prev_top*levIns*(1-fnc[0]) =
|
|
// = aux1 * (1-fnc[0])
|
|
|
|
}
|