20 |^ 15 >= 1 |^ 15 by PREPOWER:9;
then 20 |^ 15 >= 1 by NEWTON:10;
then (20 |^ 15) - 1 >= 1 - 1 by XREAL_1:9;
then (20 |^ 15) - 1 in NAT by INT_1:3;
then reconsider D = (20 |^ 15) - 1 as Nat ;
jp: 11 is prime by NAT_4:27;
tp: 31 is prime by NUMERAL2:24;
sp: 61 is prime by NUMERAL2:29;
jtc: 11,31 are_coprime by jp, tp, INT_2:30;
cp1: 11,61 are_coprime by jp, sp, INT_2:30;
cp2: 31,61 are_coprime by tp, sp, INT_2:30;
jsc: 11 * 31,61 are_coprime by cp1, cp2, EULER_1:14;
2 |^ 1 = 2 by NEWTON:5;
then 2 |^ (1 + 1) = 2 * 2 by NEWTON:6;
then 2 |^ (2 + 1) = 2 * 4 by NEWTON:6;
then 2 |^ (3 + 1) = 2 * 8 by NEWTON:6;
then dc: ( 2 |^ (4 + 1) = 2 * 16 & 3 * 11 = 32 - (- 1) ) by NEWTON:6;
then dp: 2 |^ 5, - 1 are_congruent_mod 11 by INT_1:def 5;
5 = (2 * 2) + 1 ;
then po: 5 is odd ;
reconsider J = - 1 as Integer ;
11 * 1 = 10 - (- 1) ;
then 10, - 1 are_congruent_mod 11 by INT_1:def 5;
then 10 |^ 5,(- 1) |^ 5 are_congruent_mod 11 by GR_CY_3:34;
then 10 |^ 5, - 1 are_congruent_mod 11 by po, POLYFORM:9;
then (2 |^ 5) * (10 |^ 5),J * J are_congruent_mod 11 by dp, INT_1:18;
then (2 * 10) |^ 5,1 are_congruent_mod 11 by NEWTON:7;
then (20 |^ 5) |^ 3,1 |^ 3 are_congruent_mod 11 by GR_CY_3:34;
then 20 |^ (5 * 3),1 |^ 3 are_congruent_mod 11 by NEWTON:9;
then 20 |^ 15,1 are_congruent_mod 11 by NEWTON:10;
then jd: 11 divides D by INT_1:def 4;
31 * 4 = 121 - (- 3) ;
then sd: 121, - 3 are_congruent_mod 31 by INT_1:def 5;
31 * 1 = 33 - 2 ;
then tt: 33,2 are_congruent_mod 31 by INT_1:def 5;
31 * 1 = 20 - (- 11) ;
then dw: 20, - 11 are_congruent_mod 31 by INT_1:def 5;
then 20 |^ 2,(- 11) |^ 2 are_congruent_mod 31 by GR_CY_3:34;
then 20 |^ 2,(- 11) * (- 11) are_congruent_mod 31 by WSIERP_1:1;
then 20 |^ 2, - 3 are_congruent_mod 31 by sd, INT_1:15;
then 20 * (20 |^ 2),(- 11) * (- 3) are_congruent_mod 31 by dw, INT_1:18;
then 20 |^ (2 + 1),33 are_congruent_mod 31 by NEWTON:6;
then 20 |^ 3,2 are_congruent_mod 31 by tt, INT_1:15;
then (20 |^ 3) |^ 5,2 |^ 5 are_congruent_mod 31 by GR_CY_3:34;
then dwp: 20 |^ (3 * 5),2 |^ 5 are_congruent_mod 31 by NEWTON:9;
31 * 1 = (2 |^ 5) - 1 by dc;
then 2 |^ 5,1 are_congruent_mod 31 by INT_1:def 5;
then 20 |^ 15,1 are_congruent_mod 31 by dwp, INT_1:15;
then 31 divides D by INT_1:def 4;
then jtd: 11 * 31 divides D by jd, jtc, PEPIN:4;
3 |^ (2 + 2) = (3 |^ 2) * (3 |^ 2) by NEWTON:8
.= (3 * 3) * (3 |^ 2) by WSIERP_1:1
.= (3 * 3) * (3 * 3) by WSIERP_1:1 ;
then 61 * 1 = (3 |^ 4) - 20 ;
then 3 |^ 4,20 are_congruent_mod 61 by INT_1:def 5;
then (3 |^ 4) |^ 15,20 |^ 15 are_congruent_mod 61 by GR_CY_3:34;
then 3 |^ (4 * 15),20 |^ 15 are_congruent_mod 61 by NEWTON:9;
then f: 20 |^ 15,3 |^ 60 are_congruent_mod 61 by INT_1:14;
3,61 are_coprime by sp, PEPIN:41, INT_2:30;
then ( (3 |^ (Euler 61)) mod 61 = 1 & 60 = 61 - 1 ) by EULER_2:18;
then (3 |^ 60) mod 61 = 1 by EULER_1:20, sp;
then 3 |^ 60,1 are_congruent_mod 61 by NAT_6:10;
then 20 |^ 15,1 are_congruent_mod 61 by f, INT_1:15;
then 61 divides D by INT_1:def 4;
then (11 * 31) * 61 divides D by jsc, jtd, PEPIN:4;
hence (11 * 31) * 61 divides (20 |^ 15) - 1 ; :: thesis: verum