Since that tumultuous evening in 1958, the British public has been treated to many wonderful sights: parades at Easter time from Trafalgar Square to the nuclear laboratories at Alder- maston, the Labour party torn in two by a vigorous ban-the-bomb movement, defiant rowboatfuls of young pacifists at the Holy Loch, Bertrand Russell squatting in front of the Ministry of Defence and going to jail for his trouble.

‘Are you an alienist?’ I interrupted. ‘Every doctor should be - a little,’ answered that original, imperturbably.

Neither fornicators, nor those who serve idols, nor adulterers, nor effeminate, nor the lusters after mankind […] shall obtain the kingdom of God.

…such a tree can be built up incrementally by adding the shortest edge not yet explored, which also maintains treeness (acyclicity).