library_setup_time puzzle

The followint is a slice of timing library.

.........

pin(D) {
direction : input;
nextstate_type : data;
related_ground_pin : VSS;
related_power_pin : VDD;
capacitance : 0.0009724;
rise_capacitance : 0.0009724;
fall_capacitance : 0.0009669;
timing () {
related_pin : "CP";
sdf_cond : "SDN_SDFCHK";
timing_type : setup_rising;
when : "SDN";
rise_constraint (constraint_template_3x3) {
index_1 ("0.0075, 0.0917, 0.7657");
index_2 ("0.0075, 0.0917, 0.7657");
values ( \
"0.05026, 0.07239, 0.1913", \
"0.02122, 0.04428, 0.1612", \
"-0.06691, -0.04752, 0.05172" \
);
.........


index_1 is the related_pin_transition ( the transition of CP pin?), index_2 is constrainted_pin_transition (the transition of D pin?);

My question is what's the order of index_1 and index_2 for values ? How I can get this information from library?

If the following order is right (see the figure), why the library_setup increase with index_1(clk pin transtion time) increase, but decrease with index_2(D pin transtion) increase.
In my opinion, the setup time should increase which the increase of D pin transtion time and decrease with the increase of CP pin transtion time.

index1
--------------------->
| i
| n
| d
| e
| x
| 2
|
v

Thanks for your consideration.

The table is organized in this order :
" (1,1) , (1,2) , (1,3) " ,
" (2,1) , (2,2) , (2,3) " ,
" (3,1) , (3,2) , (3,3) "