function rejectAt(x, ks)
// x:  lists
// ks: keys

const xlists = require('extra-lists');

var x = [['a', 'b', 'c', 'd', 'e'], [1, 2, 3, 4, 5]];
xlists.rejectAt(x, ['a', 'c', 'e']);
// → [ [ 'b', 'd' ], [ 2, 4 ] ]

xlists.rejectAt(x, ['b', 'd']);
// → [ [ 'a', 'c', 'e' ], [ 1, 3, 5 ] ]