Growth problems for avoidable words
Theoretical Computer Science
Decision problems for patterns
Journal of Computer and System Sciences
Handbook of formal languages, vol. 1
A non-learnable class of E-pattern languages
Theoretical Computer Science - Algorithmic learning theory(ALT 2002)
Unambiguous Erasing Morphisms in Free Monoids
SOFSEM '09 Proceedings of the 35th Conference on Current Trends in Theory and Practice of Computer Science
Theoretical Computer Science
The unambiguity of segmented morphisms
Discrete Applied Mathematics
Hi-index | 0.00 |
A segmented morphism σn : Δ* → {a, b}*, n ∈ N, maps each symbol in Δ onto a word which consists of n distinct subwords in ab+a. In the present paper, we examine the impact of n on the unambiguity of σn with respect to any α ∈ Δ+, i. e. the question of whether there does not exist a morphism τ satisfying τ(α) = σn(α) and, for some symbol x in α, τ(x) ≠ σn(x). To this end, we consider the set U(σn) of those α ∈ Δ+ with respect to which σn is unambiguous, and we comprehensively describe its relation to any U(σm), m ≠ n. Our paper thus contributes fundamental (and, in parts, fairly counter-intuitive) results to the recently initiated research on the ambiguity of morphisms.