quae_antea: Quae Antea

In eratosthenes: Archaeological Synchronism

Quae Antea

Description

For a list of multiple partial sequences (of vector objects), generate another list which, for each element, gives the elements that occur before it ("quae antea"). This is analogous to a recursive trace through all partial sequences from right to left. An element "alpha" is added to all sets to avoid empty vectors. See also quae_postea.

Usage

quae_antea(obj)

## S3 method for class 'list'
quae_antea(obj)

Arguments

obj	A list of vector objects which represent ordered sequences.

Value

A list of vector objects, which contain the elements that occur before any one given element in the input sequences.

Examples

x <- c("A", "B", "C")
y <- c("B", "D", "E", "C", "F")
z <- c("C", "G")
a <- list(x, y, z)

quae_antea(a)

eratosthenes documentation built on June 28, 2025, 1:08 a.m.