) the shrug is a poor foundation upon which to build so important a theory, for previously to the Revolution the gesture was unknown. I have not a doubt that it is directly referable to the terror inspired by the guillotine during the period of that instrument's activity.

Xi (upper case Ξ, lower case ξ) is the 14th letter of the Greek alphabet. It is pronounced by English speakers, but by ancient and modern Greeks. The modern Greek pronunciation has also become fairly common among mathematicians, even speaking in English.

the cardinal number that is the sum of ten and one

being one more than ten