Given typed ACSets phi_1: X_1 -> T and phi_2: X_2 -> T (over the same type system), compute their typed product via pullback over T.
Details
For each object ob, the product contains pairs (x1, x2) where phi_1(x1) == phi_2(x2). This is the categorical pullback in the slice category ACSet/T.
Examples
T <- Graph()
add_vertices(T, 2)
#> [1] 1 2
add_edge(T, 1, 2)
#> [1] 1
g1 <- Graph()
add_vertices(g1, 2)
#> [1] 1 2
add_edge(g1, 1, 2)
#> [1] 1
t1 <- typed_acset(g1, T, V = c(1L, 2L), E = 1L)
g2 <- Graph()
add_vertices(g2, 2)
#> [1] 1 2
add_edge(g2, 1, 2)
#> [1] 1
t2 <- typed_acset(g2, T, V = c(1L, 2L), E = 1L)
tp <- typed_product(t1, t2)
nv(flatten_typed(tp))
#> [1] 2