Frieze Patterns
Frieze patterns have a translational symmetry, so that they repeat
and form a strip. There are only seven possible kinds of frieze
symmetry.
None of the 7 frieze symmetry groups is particularly hard to find
at the Cathedral. Surprisingly (since it has very little symmetry),
p111 may be the most rare.
p111
This has only a translation symmetry.

Blessed Sacrament Chapel, wall.

Outside.
p112
This has a translation, as well as 180 degree rotations evenly spaced.

Central Dome, pulpit detail.
p1m1
This has a translation, and a reflection line down the center.

Narthex, on pillar.

Bishop's Hall, ceiling.
pm11
This has a translation, and evenly spaced reflections crossing the pattern.

Narthex, wall.

Central Dome, pulpit detail.
pmm2
This has a translation, evenly spaced reflections crossing the pattern,
a reflection line down the center, and 180 degree rotations.

All Saints Chapel, floor.
p1a1
This has a glide reflection.

Blessed Sacrament Chapel, wall.

Blessed Virgin's Chapel, floor.
pma2
This has a glide reflection, evenly spaced reflectons crossing the pattern,
and 180 degree rotations.

Southeast corner (outside), gate.