set F = AffineMap (1,(- i));
set f = (AffineMap (1,(- i))) | ].(0 + i),((0 + i) + p1).[;
A1:
the carrier of (R^1 | (R^1 ].0,1.[)) = R^1 ].0,1.[
by PRE_TOPC:8;
dom (AffineMap (1,(- i))) = REAL
by FUNCT_2:def 1;
then A2:
dom ((AffineMap (1,(- i))) | ].(0 + i),((0 + i) + p1).[) = ].i,(i + 1).[
by RELAT_1:62;
A3:
rng ((AffineMap (1,(- i))) | ].(0 + i),((0 + i) + p1).[) = ].0,(0 + 1).[
by Lm24;
the carrier of (R^1 | (R^1 ].i,(i + 1).[)) = R^1 ].i,(i + 1).[
by PRE_TOPC:8;
then reconsider f = (AffineMap (1,(- i))) | ].(0 + i),((0 + i) + p1).[ as Function of (R^1 | (R^1 ].i,(i + p1).[)),(R^1 | (R^1 ].0,(0 + p1).[)) by A1, A2, A3, FUNCT_2:2;
A4:
CircleMap (R^1 (0 + i)) = (CircleMap (R^1 0)) * f
by Th41;
A5:
R^1 | (R^1 (rng (AffineMap (1,(- i))))) = R^1
by Lm12;
A6: CircleMap . (R^1 i) =
c[10]
by Th32
.=
CircleMap . (R^1 0)
by Th32
;
A7:
R^1 | (R^1 (dom (AffineMap (1,(- i))))) = R^1
by Lm12;
A8:
R^1 (AffineMap (1,(- i))) = AffineMap (1,(- i))
;
f is onto
by A1, A3;
then
f is open
by A7, A5, A8, TOPREALA:10;
hence
CircleMap (R^1 i) is open
by A4, A6, Lm63, TOPREALA:11; verum