[add] fld logical formula task (#1931)

lm_eval/tasks/fld/README.md

@@ -38,18 +38,19 @@ Homepage: https://github.com/hitachi-nlp/FLD
 
 ### Groups and Tasks
 
-#### Groups
-
-* `fld`
-
-#### Tasks
-
 This release is the simplified version of FLD where a model is required to predict only an answer.
 This setting is described by "answer accuracy" in the original paper.
 
+#### Tasks in Group `fld`
 * `fld_default` is a basic task based on [FLD.v2](https://huggingface.co/datasets/hitachi-nlp/FLD.v2/viewer/star)
 * `fld_star`: is a more challenging version based on [FLD.v2-star](https://huggingface.co/datasets/hitachi-nlp/FLD.v2/viewer/star)
 
+#### Tasks in Group `fld_logical_formula`
+Further, we have "logical formula" versions of the benchmarks, which evaluate LLMs' pure logical reasoning capabilities within the domain of logical formulas, rather than natural language:
+* `fld_logical_formula_default`
+* `fld_logical_formula_fld_star`
+
+
 ### Checklist
 
 For adding novel benchmarks/datasets to the library:

lm_eval/tasks/fld/fld_logical_formula_default.yaml

+group:
+  - fld_logical_formula
+task: fld_logical_formula_default
+dataset_path: hitachi-nlp/FLD.v2
+dataset_name: default
+training_split: train
+validation_split: validation
+test_split: test
+doc_to_text: "Based on the provided facts ($context$), either prove or disprove the hypothesis or state that it is unknown. The facts and the hypothesis are written in logical formulas as follows: capital letters such as \"{A}\", \"{B}\", \"{AB}\" are predicates, small letters such as \"{a}\", \"{b}\", \"{ab}\" are constants, \"&\" is logical conjunction, \"v\" is logical disjunction, \"¬\" is negation, \"->\" is implication, \"(x)\" is \"for all x\", and \"(Ex)\" is \"for some x\". $hypothesis$ = {{hypothesis_formula}} ; $context$ = {{context_formula}} ; $proof$ = "
+doc_to_target: world_assump_label
+metric_list:
+  - metric: exact_match
+    aggregation: mean
+    higher_is_better: true
+filter_list:
+  - name: remove_whitespace
+    filter:
+      - function: remove_whitespace
+      - function: take_first
+metadata:
+  version: 2.0

lm_eval/tasks/fld/fld_logical_formula_star.yaml

+include: fld_logical_formula_default.yaml
+task: fld_logical_formula_star
+dataset_name: star