thermA4Slot property

Implementation

String get thermA4Slot => isNL
    ? 'Beide R_ac en T₁ dalen bij groter A; I stijgt niet lineair. Vandaar de niet-lineaire doorsnede-stroom relatie in de catalogus.'
    : 'Both R_ac and T₁ decrease with larger A; I does not increase linearly. Hence the non-linear cross-section-current relationship in the catalogue.';