thus
Sum (digits (4975,10)) = 25
by Th1376; NUMBER11:def 1 ( 25 divides 4975 & ( for m being Nat st Sum (digits (m,10)) = 25 & 25 divides m holds
4975 <= m ) )
4975 = 199 * 25
;
hence
25 divides 4975
by INT_1:def 3; for m being Nat st Sum (digits (m,10)) = 25 & 25 divides m holds
4975 <= m
let m be Nat; ( Sum (digits (m,10)) = 25 & 25 divides m implies 4975 <= m )
assume A1:
( Sum (digits (m,10)) = 25 & 25 divides m )
; 4975 <= m
then consider j being Nat such that
A2:
m = 25 * j
by NAT_D:def 3;
assume
m < 4975
; contradiction
then
25 * j < 25 * 199
by A2;
then
j < 198 + 1
by XREAL_1:64;
then
j <= 198
by NAT_1:9;
then
( j <= 99 or ( j >= 99 + 1 & j <= 198 ) )
by NAT_1:9;
then
( not not j = 0 & ... & not j = 99 or not not j = 100 & ... & not j = 198 )
;
per cases then
( j = 0 or j = 1 or j = 2 or j = 3 or j = 4 or j = 5 or j = 6 or j = 7 or j = 8 or j = 9 or j = 10 or j = 11 or j = 12 or j = 13 or j = 14 or j = 15 or j = 16 or j = 17 or j = 18 or j = 19 or j = 20 or j = 21 or j = 22 or j = 23 or j = 24 or j = 25 or j = 26 or j = 27 or j = 28 or j = 29 or j = 30 or j = 31 or j = 32 or j = 33 or j = 34 or j = 35 or j = 36 or j = 37 or j = 38 or j = 39 or j = 40 or j = 41 or j = 42 or j = 43 or j = 44 or j = 45 or j = 46 or j = 47 or j = 48 or j = 49 or j = 50 or j = 51 or j = 52 or j = 53 or j = 54 or j = 55 or j = 56 or j = 57 or j = 58 or j = 59 or j = 60 or j = 61 or j = 62 or j = 63 or j = 64 or j = 65 or j = 66 or j = 67 or j = 68 or j = 69 or j = 70 or j = 71 or j = 72 or j = 73 or j = 74 or j = 75 or j = 76 or j = 77 or j = 78 or j = 79 or j = 80 or j = 81 or j = 82 or j = 83 or j = 84 or j = 85 or j = 86 or j = 87 or j = 88 or j = 89 or j = 90 or j = 91 or j = 92 or j = 93 or j = 94 or j = 95 or j = 96 or j = 97 or j = 98 or j = 99 or j = 100 or j = 101 or j = 102 or j = 103 or j = 104 or j = 105 or j = 106 or j = 107 or j = 108 or j = 109 or j = 110 or j = 111 or j = 112 or j = 113 or j = 114 or j = 115 or j = 116 or j = 117 or j = 118 or j = 119 or j = 120 or j = 121 or j = 122 or j = 123 or j = 124 or j = 125 or j = 126 or j = 127 or j = 128 or j = 129 or j = 130 or j = 131 or j = 132 or j = 133 or j = 134 or j = 135 or j = 136 or j = 137 or j = 138 or j = 139 or j = 140 or j = 141 or j = 142 or j = 143 or j = 144 or j = 145 or j = 146 or j = 147 or j = 148 or j = 149 or j = 150 or j = 151 or j = 152 or j = 153 or j = 154 or j = 155 or j = 156 or j = 157 or j = 158 or j = 159 or j = 160 or j = 161 or j = 162 or j = 163 or j = 164 or j = 165 or j = 166 or j = 167 or j = 168 or j = 169 or j = 170 or j = 171 or j = 172 or j = 173 or j = 174 or j = 175 or j = 176 or j = 177 or j = 178 or j = 179 or j = 180 or j = 181 or j = 182 or j = 183 or j = 184 or j = 185 or j = 186 or j = 187 or j = 188 or j = 189 or j = 190 or j = 191 or j = 192 or j = 193 or j = 194 or j = 195 or j = 196 or j = 197 or j = 198 )
;
end;