An audio decoder (200; 800;2200) for providing a decoded audio information (212; 812) on the basis of an encoded audio information (210; 810), the audio decoder comprising: an arithmetic decoder (230; 820; 2220) for providing a plurality of decoded spectral values (232; 822; 2224) on the basis of an arithmetically-encoded representation (222; 821; 2222) of the spectral values; and a frequency-domain-to-time-domain converter (260; 830; 2230) for providing a time-domain audio representation (262; 812; 2212) using the decoded spectral values (232; 822; 2224), in order to obtain the decoded audio information (212; 812; 2212); wherein the arithmetic decoder (230; 820; 2220) is configured to select a mapping rule (297; cum_freq[]) describing a mapping of a code value (value) of the arithmetically-encoded representation of the spectral values onto a symbol code (symbol) representing one or more of the decoded spectral values, or at least a portion of one or more of the decoded spectral values, in dependence on a numeric current context value (s) describing a current context state, wherein the arithmetic decoder is configured to determine the numeric current context value (s) in dependence on a plurality of previously decoded spectral values (a); wherein the arithmetic decoder is configured to evaluate at least one table (ari_s_hash;ari_gs_hash) using an iterative interval size reduction (542; 546), to determine whether the numeric current context value (s) is identical to a table context value described by an entry (j, ari_s_hash[i], ari_gs_hash[i]) of the table or lies within an interval described by entries of the table, and to derive a mapping rule index value (pki) describing a selected mapping rule (arith_cf_m[pki]). an arithmetic decoder (230; 820; 2220) for providing a plurality of decoded spectral values (232; 822; 2224) on the basis of an arithmetically-encoded representation (222; 821; 2222) of the spectral values; and a frequency-domain-to-time-domain converter (260; 830; 2230) for providing a time-domain audio representation (262; 812; 2212) using the decoded spectral values (232; 822; 2224), in order to obtain the decoded audio information (212; 812; 2212); wherein the arithmetic decoder (230; 820; 2220) is configured to select a mapping rule (297; cum_freq[]) describing a mapping of a code value (value) of the arithmetically-encoded representation of the spectral values onto a symbol code (symbol) representing one or more of the decoded spectral values, or at least a portion of one or more of the decoded spectral values, in dependence on a numeric current context value (s) describing a current context state, wherein the arithmetic decoder is configured to determine the numeric current context value (s) in dependence on a plurality of previously decoded spectral values (a); wherein the arithmetic decoder is configured to evaluate at least one table (ari_s_hash;ari_gs_hash) using an iterative interval size reduction (542; 546), to determine whether the numeric current context value (s) is identical to a table context value described by an entry (j, ari_s_hash[i], ari_gs_hash[i]) of the table or lies within an interval described by entries of the table, and to derive a mapping rule index value (pki) describing a selected mapping rule (arith_cf_m[pki]).